This example describes an electronic insect lamp circuit makes use of the moths and other pests phototaxis, induced by light, high pressure shock method to kill pests. The device can automatically turn on at night, during the day and can automatically shut down.
Circuit Work
The e-pest control light from the light control circuit switches, and voltage doubling rectifier circuit, as shown.

Circuit, the light control switch circuit by the photosensitive resistor RG, the capacitor CO, lamp EL, resistor R, two-way trigger diode and the thyristor V VT composition; double voltage rectifier circuit by the capacitor Cl of a C5 and a V rectifier diode VD1 D5 composition.
In the daytime, RG was affected by light exposure to the low resistance state, the CO short-circuit, VT without triggering voltage is off, voltage rectifier circuit does not work. When no light exposure at night, RG resume high-impedance state, AC 220V voltage by the EL and R charge of the CO, when the voltage charge on the CO to a certain value, V conduction, so that VT triggered by conduction, doubler rectifier circuit power work. AC 220V voltage doubler rectifier circuit by the pressure of five times the rectifier, the resulting increase of about 1450V high-voltage power line stubble. When a flying insect phototaxis to touch the grid, the pressure will immediately be killed.
Component selection
R 1W metal film resistors used.
RG selected series of photosensitive resistor MGL, the light resistance should be less than or equal to 3 kfl, dark resistance is greater than or equal to 5Mn.
CO polyester selected capacitor voltage is 160V; C1 C5 are selected voltage value of a 600V high-voltage paper capacitor or CBB capacitor.
VD1 VD5 are made of a type 1 N4007 diode rectifier.
DB3 or 2CTS V series use two-way trigger diode.
VT or TCL336A use 3 CTS3/600 V-type (3A, 600V) of the bidirectional thyristor.
Use 3W white EL lamp cold cathode type.
Power Network, the outer layers made of metal mesh: the inner metal wire spacing is small (about 2mm), used for hunting smaller size of the black-tailed leafhopper, rice thrips, planthoppers, White-winged leafhopper and other pests; outer metal mesh spacing is large (about lomm), used for hunting large Sesamia inferens body, stem borer, yellow rice borer, pests, etc. Regardless thread.

Here are the new hypnosis can be issued two-rain sound effects sound very good hypnotic effect.
1. Circuit Theory
Hypnotic sound of rain electronic circuit device shown in Figure 1. Circuit consists of: high voltage generator, rectifier and two neon bulb relaxation oscillator components.
High-voltage generator consists of transistor VT, coils L1-L3 etc., press the switch "SB" after, L1, L2 and the inductance component VT immediate feedback from the oscillator oscillator, the oscillation coil L by the step-up voltage gain of about 300 V of hypertension. This high-pressure rectification by the diode VD, charging the capacitor C1, so the two ends of the capacitor C1 high voltage DC source available. Neon bulb V1, piezoelectric ceramics B1, resistor R2 and V2, B2, R3, respectively, composed of two relaxation oscillator start-up principle: C1 of the DC high voltage source through resistor R2, R3, respectively, of piezoelectric ceramic to the B1, B2 Charge (HTD ~ 27 A film about 0.017uF ceramic electric capacity), when the voltage charge to the neon bulb V1 (or V2) of the striking voltage (about 60 ~ 80 V), the neon bulb discharge conduction, piezoelectric accumulated charge on the ceramic plate was discharge, voltage drop, when the reduced voltage starter neon bulbs, neon bulbs glow was off to stop the state, piezoelectric ceramics will continue through the resistor R2, R3 charging, the voltage continuously up ... ... again and again the formation of oscillation. Piezoelectric ceramics in the discharge process, which changes the voltage across a larger, due to piezoelectric effect, piezoelectric ceramics to mechanical vibrations, which issued a similar rain to the sound of "Ka, Ka" sound.

2. Component selection and production
VT can be used such as germanium PNP transistor type 3AX31B, β ≥ 50, VD can be used such as silicon rectifier diodes 1N4007 type, V1, V2, etc. can be NH0-4L-type voltage 60 ~ 80V starter about neon bubbles.
R1 ~ R3 are used RTX-118W carbon film resistors, such as high resistance can not find the 100 MΩ resistor, you can use a number of resistors in series. C1 requires a pressure of more than 400 V electrolytic capacitors. Transformer T need to self: use of magnetic tank GU18 wound, L1 turn around 20, L2 30 turns around, L3 around 500 turns, are used Φ0.1 mm high-strength polyester enameled wire wound. G with a large battery, "SB" for small touch of a button normally open switch, piezoelectric ceramics can be HTD-27A type.
The road is relatively simple mechanical and electrical, do not produce printed circuit boards, can be directly used in the plastic machine box frame connection wiring installation. To increase the volume, should be made to the piezoelectric ceramic to help tune a plastic, plastic machines can also open a box the size of the hole slightly smaller than the ceramic, piezoelectric ceramic plate and then paste in the hole with epoxy resin on the use of machines for the help box tune, the effect is also very good.
3. Circuit debugging
First, adjust the resistance R, the voltage on the capacitor C1 in the 250-300 V or so, if the transfer does not always go up the voltage may be too little number of turns the coil L3. If absolutely no voltage across C1, then there is no start-up high-voltage generator, coils L1 and L2 may be the termination of the same name wrong, as long as the L1 (or L2) can be solved two thread about reversed. Resistance of L2 (or L3) of the resistance, piezoelectric ceramic B1 (or B2) of the capacitor value will determine the level of oscillation frequency, if the piezoelectric ceramic capacitor value is too small, rain will affect the hypnotic effect the sound frequency is too high , this time as long as the resistor R2 (or R3) in the resistance to take a large can be solved.
4. Use
Just click the switch before going to sleep "SB", full of high-voltage capacitor C1 Jibei. Two relaxation oscillator start-up began, due to the discrete circuit elements, the oscillation frequency of two oscillators can not be completely consistent, it can produce double the sound rain sound. Just press the switch in the "SB", the sound of rain from low to high frequency, indicating that the voltage across C1 increases by about 4 ~ 5 s (seconds), the rise in tone, indicating that the voltage across C1 is charge to the highest value. Release the "SB", the hypnotic sound of the wooden fish sound a bit like a temple, later as the voltage drop across C1, resulting in reduced hypnotic voice tone, sounds like rain. Later, as the whereabouts of the two roof dripping off the sound in the tank, a drop of water before chasing after the sound of a drop of water, which is the reason the two different oscillator frequency. When a drop to about one second, C1 is less than the voltage across the starter piezoelectric voltage, the circuit to stop vibration, piezoelectric ceramic is no longer audible. Circuit is no longer consumes power. If this If we can not fall asleep, you can press the switch "SB". As the neon bulb relaxation oscillator work, a very provincial power, so each click on SB, the circuit can work for 40 ~ 50min (minutes). If you need to work longer hours, can increase the capacity of capacitor C1. If the capacitor C1, the larger leakage current will significantly reduce the work of the circuit after each key time, so in the choice of C1 must pay attention to the size of the leakage current.

Now the gas stove, water heater, etc. Most electronic ignition, it is easy to operate, safe, reliable, etc., the type of electronic ignition gas more, but the basic structure and principle of the circuit very much the same. This paper describes a simple structure, manufacture and convenient electronic ignition, gas stove manufacturer for electronic enthusiasts reference.

Working:
The device is shown in Figure 1 ( click to download schematic diagram ). It is by the oscillator, high voltage rectifier circuit and the booster composition. VT and the transistor T1 of the L1, L2, R component oscillator, power switch S, VT will oscillate, so in the L3 T1 induces a higher voltage side, the half-wave rectifier diode VD, after charging the capacitor C , while in T2, L5-side induced a higher electrical pulse ignition. When the S dial to "2" stalls, C to maintain the charge in the discharge state, until reliable the gas ignited. The action only in a few seconds to complete.
Selection and production of components
E 5 with a battery. VT uses germanium transistors 3AX81, to improve the pressure drop characteristics under low voltage, such as silicon tube is larger pressure drop, efficiency decreased significantly. VD series of high-voltage silicon particles with 2DG, the back pressure is greater than 250V, C the capacity in the range of 0.47-0.68uF, the pressure is greater than 160V. T1 can be a small transistor radio in the input or output transformer 5 × 7-E core, L1 with Φ0.17mm high intensity around the 30 turns enameled wire, L2 with the same diameter of around 60 turns of enameled wire, L3 with high Φ0.06mm 3500 turns around the strength of enameled wire. T2 used for the core 40mm long magnets, magnet wire in the first bar magnet with Φ0.41mm around the 17 turns on for L4, L4 and then set into the plastic slot on the frame, and use Φ0.06mm enameled high strength around the skeleton 1500 turns. Skeleton consists of trough 10, around 150 turns in each trough, which can effectively prevent the high-pressure breakdown L5 itself.
After the circuit system can be access at both ends of the electrode in the L5, placed an appropriate distance, toggle S, see flashing spark between two electrodes will come to success.

As living standards improve, people's growing awareness of health, blood pressure is often health care, early detection of diseases one of the principal means. At present, although there have been several significant electronic device available, but the price is high, relatively large measurement errors, the most accurate or traditional desktop mercury sphygmomanometer, blood pressure table pointer followed. Both blood pressure (Table) accounted for the amount of the current society has more than 90% of patients blood pressure the doctor for the main equipment. Home ownership are also high. However, this requires a stethoscope sphygmomanometer aided measurement of blood pressure, and there should be some measurement techniques, especially for diastolic blood pressure (commonly known as low-voltage) of the judge, the larger human error factors. This paper describes a measurement of electronic aids, for a self-made electronics enthusiasts. The auxiliary measurement device can accurately measure blood pressure becomes easy to not only replace the stethoscope, you can also observe the blood pressure values. Measurement techniques so that people who do not understand can be measured quasi-blood pressure.

How it works:
      Circuit shown in Figure 1, collected by sound waves measuring devices, voltage amplification, low pass filtering, wave conversion, voltage detection, sound and light show circuit.

HTD1 the detected pulse wave signal is sent to the gate of V1, in this, V1 impedance transformation from the role. The high resistance of the weak acoustic signal voltage transformation to a low impedance output, the C1, C2, C4 coupled to IC1. IC1 for the quad op amp, its foot internal circuit and external components, the voltage amplifier, adjust the resistance R8 to change the magnification level. The amplified audio signal through R9, C6 coupled to feet inside and outside the low-pass filter circuit, eliminating the human body sensors and external interference signals. And increase the load capacity.feet from the signal output, coupled by C8 to 12, 13, 14 feet for shaping amplification, will transform a square wave pulse wave output from 14 feet. W1 put a lot of adjustment can be changed. 14 feet square wave output signal directly coupled to IC2's feet and 12 feet. Amplified by two operational amplifiers, respectively, and 14 feet from the pin output. feet square wave voltage output coupled to the IC3 by D6 of 12,13 feet. IC3 into four NAND gate circuit, when the 12 and 13 feet is high, pin output low. D7 LED indicator. Adjust the capacity of C12, can change the delay time of the luminous D7. IC2 14-foot high square wave pulse output coupled to the IC3 via the D5 feet, its oscillator circuits inside and outside the foot. pin is high when the oscillator start-up, make noise, the oscillation frequency of about 2000Hz. V2 and IC2's feet from the sound and light circuits simultaneously and so on.
    IC1's  foot circuits voltage detectors, battery voltage is too low

 

Component Selection:
      HTD1 use 27mm piezoelectric ceramics. IC1, IC2 LM324 quad op amp selection. Four CD4011 IC3 and non-selected door, D1 use 4.5V regulator, HTD2 use 15mm piezoelectric ceramic sounder, K use mini toggle switch. Red light-emitting diodes using a micro-D2, D7 highlighted with a mini blue LED, power supply by four AA batteries, and the remaining components as shown.

Installation:
      All components soldered in Figure 2, printed circuit board, into the corresponding plastic box, HTD1 fixed in the appropriate size stainless steel or plastic case, the use of shielded cable and the 3.5mm plug is connected with the measurement, adjust the sensitivity over W1 but do not have high self-oscillation; will take down the battery, switch to adjustable voltage power supply. The voltage to 4.8 V. W2 D1 adjusted so that light can be just.

Schematic of the V1, R1 are encapsulated within the sensor HTD1. It does not draw on the PCB V1, R1 position.

Usage:
      When used, the blood pressure arm band on the arm. Brought down on the arm of the probe HTD1 the brachial artery. When the pressure is estimated that more than systolic blood pressure (commonly known as high-voltage) 2.5 ~ 4kPa (20 ~ 30mmHg) or so, stop the pressure, playing an open valve slowly deflated, systolic blood pressure when the pressure drops, the measurement starts to sound, light direction At this time displayed on the blood pressure is systolic blood pressure, its sound and light are synchronized with the pulse of the beat, sound and light stops shown on the blood pressure is diastolic blood pressure.

My father was suffering from headaches, back pain and other chronic diseases, often need to acupuncture. Last year, travel, see the section acupuncture pen, design resembling a mouse, a novel, is pleased to repurchase. The use of the treatment is good.
I analyze its (the circuit as shown in photo). Works as follows for the music integrated circuit IC1, K1 is closed, IC1 output of the audio current through BG1-BG3 amplified by the step-up transformer B1, secondary high voltage output of about 200V. Then divided into AC and DC two blocked. AC high-voltage AC output directly to the block needle contact, appropriate adjustment w2, when contact with human skin contact, can produce a strong stimulation, because the AC has the skin effect, the treatment can only act on the skin surface. By the AC high voltage DC block by D1 ~ D4, C2 consisting of rectifier, filter circuit produces an output to the contact and output sockets, the use of acupuncture patch, patch spacing adjustment based on just the w2 to LED2 is lit, the treatment can reach deep purposes.

In this paper to recommend a practical, low-cost automatic wash and automatic hand dryer circuit.
1, automatic hand washer
Automatic hand washer of the circuit shown in Fig.
220V AC circuit by the step-down transformer T, into a low-voltage alternating current, the rectifier filter, a low voltage DC, and then by 7806 three-terminal integrated circuit voltage regulator, 6V DC supplied by the control circuit. H1 in red light-emitting diode, as the power indicator. N2 for the infrared receiver circuit SFH506-38, N3 audio decoder for the phase-locked loop LM567, N3 and R3, C6 component oscillator, R3, R6 decided N3 center frequency of the internal VCO, LM567 3-pin input end, 8-pin to a logic output, the output side door for the OC output, the maximum sink current is 100mA, LM567 working voltage of 4.75V ~ 9V, the operating frequency from a few tenths of Hz to 500 kHz, quiescent current of 8mA . N4 for the NE555 timer, it with external components form a single-shot timing circuit, which is aimed at staff occasionally deviated from the infrared detection range, the device can ensure the normal water wash.
LM567 chip oscillation signal output 5 pin power amplified by the transistor, to promote the VD out infrared emitting diodes infrared emission. No one hand, the infrared receiver circuit receiving less than N2 VD out the infrared emission, N3 3 feet without signal input, 8 feet high, N4 3 feet low, the transistor cut-off, relay K-off Power in the release state, the solenoid valve Y does not move, wash no water release device. When the staff when placed under the hand washer, N2 receives the reflected infrared and manpower amplified by the N2, N3 3 input to the feet, after internal processing by the N3 to N3 of the 8-pin output low, so that the lower trigger N4 2 feet into the low potential side, resulting in output of N4 3 feet high, the transistor turns on, relay J1 pull, so normally open contacts closed, solenoid valve connected to the 220V AC power supply Y, Y began to move, release water to wash device for use in washing people, and issued a green light-emitting diode LED2 to indicate hand washer is working on drainage condition. Washing is completed, after the staff left hand washer, N4 reset after a few seconds delay, so wash your hands to stop water.
Figure 1, transformer T with 220V/9V small AC adapter, VD for the PH303 infrared emitting diodes, VT1 for the 8050 transistor, VT2 to 9013 transistors, J1 with JRX-13F, 6V small DC relay, Y using commercially available 220V AC solenoid valve, and the remaining components in the model and the data shown in Figure 1, the standard parameters.
User error response : The PDF data access components, graph integration of one infrared receiver "SFH506-38" pin marked in error, be amended to: 1 pin GND, 2 pin VCC, 3 feet OUT. Thanks that!

 

2, automatic hand dryer
Automatic hand dryer circuit shown in Figure II, part of the circuit by the infrared transmitter and infrared receiver control part.
Part of infrared emission produced by the time base circuit 555 frequency 5kHz, 50% duty cycle square wave signal to drive the infrared emission infrared emission control.
Hand dryers in the hand placed lower, due to hand on the infrared reflectivity, receiver circuit PH302 will receive the infrared signal into by IC1, IC2, IC3 composed of selected frequency amplifier output signal is amplified , plastic, filter into a DC signal into the comparator IC4. Comparator threshold voltage of 7V, set high, which aims to improve the circuit's immunity to
Force. When the input level IC4 than 7V, the output goes low, trigger IC5 timer starts timing, while the timer goes high to 3 feet, so 3DG130 turn, pull the relay contacts , connected to the resistance wire and the fans. 2 feet to set the timer manual switch S1, can be manually operated, can also be cold or hot air through the S2 selection.

This automatic air freshener, or in indoor air pollution has reached a certain concentration of harmful gases, automatic negative oxygen ions to keep the air fresh.
  Work

Circuit shown in Figure 1 ( Click here to download the schematic diagram ). Circuit is divided into two parts, the QM-N5 as the central element of the circuit air detection switch circuit, it can detect combustible gases. When the room reaches a certain concentration of harmful gases, due to increase in the VT1 B saturation point potential conduction, played the role of the detection switch. Rt negative temperature coefficient thermistor is used to compensate for QM-N5 as the deviation caused by temperature changes. To TWH8751 circuit device as the center of negative oxygen ion generator, the oscillation frequency is about 1KHz, available in the T2 secondary pressure of about 5kV. The open discharge end, greatly improving the concentration of negative oxygen ions, reducing the concentration of ozone, so get out of negative oxygen ions increases, TWH8751 of ? inverting input pin is high potential, with the oscillator stopped in Under normal indoor environment, A, B between the resistance of a large, B point potential is very low, VT1 end, TWH8751 the feet high potential, the oscillator does not work, do not generate negative ions; when the indoor concentrations of harmful gases than the RP set given threshold, VT1 saturated conduction, TWH8751 the feet were low, the oscillator start-up, negative oxygen ions. To some extent, negative ions to eliminate indoor smoke, fresh air is conducive to good health.
  Selection and production of components
  Parts list below.

T2 14-inch line with a restructuring of the output transformer, the coil does not move, remove all the low-voltage windings, with F = 0.6mm magnet wire around the 45 re-turns. No special requirements other components. Made with the pin terminal discharge, in the long 170mm, width 40mm drill three rows of Bonded Copper eyes, each row 16, are F = 1mm. The pins one by one into the hole and weld it, to make the joints smooth, can not have glitches. Selection pin to the attention of the same length, and the more pointed tip better. Machine into a 180 × 110 × 80 ( mm3 ) of ABS plastic box. When using an adjustable knob to make the whole RP have the right sensitivity. Put the device places such as smoking regular coffee table, desk, lighting fires for the winter indoor home, can place it on the bed at night, keep fresh air during sleep.

This article describes a device to make bonsai rockery, trees produce around the layers of mist, like clouds floating in the mountains, greatly enhancing the ornamental value. Also suitable for dry conditions over the air humidification to Win breathing; the water by adding an appropriate amount of a solvent, to the disinfection of contaminated living environment to prevent diseases (such as the life time spray with vinegar, can prevent flu ) and so on.
Work
  Circuit such as the photo shows.

Mainly by the ultrasonic generator, the water level controller, power circuit composed of several parts. Ultrasonic generator constituted mainly by the transistor VT1, VT1 and its peripheral components composed of three-point capacitance LC oscillator, B is the ultrasonic transducer, and its natural frequency fc = 1.65MHz, capacitors C1, C2 decision oscillation amplitude, slightly lower than its natural frequency fc, L1, C2 is a positive feedback components, the natural frequency slightly higher than fc, VD5 protection diodes for the VT1. B because when immersed in water atomization, the water level controller from VT2, VT3 and other components of composition, role is to:
(1) for the oscillator circuit to provide base bias current;
(2) When the bonsai in water level below the set value, so that stops the oscillator, since the protective effect. VT2, VT3 take into composite pipe, through L3, R3 provides base bias to the current VT1, L3 for the high-frequency choke coil to prevent the ultrasonic signals into the level control circuit. Adjust the resistance R1 can change the VT1 of the base current to control the whole operating current. a, b for the water level control lines, usually submerged in water. Nebulizer to work, if the water level drops to a certain extent, a, b from the surface of the water, VT2, VT3 will end, the water level controller to stop providing base current to the VT1, machine stopped working.
Component selection
  VT1 quality is the key to successful production of the best produced by the Italian SGS BU406, BU407 or BU408 and other high-power high frequency transistors, requiring fT = 100MHz; VT2, VT3 and other available 9014-type NPN silicon tube, requires ß = 100; VD1 ~ VD4 available 1N4002 rectifier diodes.
  Best of all resistors used in all RJ-0.25W metal film resistors; capacitor with CBB-100V polystyrene capacitor; inductor L1 can be used in the f10 × 10mm f0.51mm enameled wire wound 27 turns on the core, inductance of about 24µH; L2 with f0. 69mm enameled wire around 2.5 turns in the f6mm bit, and then remove the womb, the inductor is about 0.22µH; L3 color code available 270µH inductor; transducer B is a key component, should be used f20 × 1.25mm/1.65MHz or f20 × 1.2mm / 1.7MHz high-intensity piezoelectric ceramics; the transformer secondary voltage of T requires 50V, power 40W; S with a small rocker switch; VT1 best to install the radiator; transducer B can not be away from the water power, or they will burn. Bonsai 4 ~ 6cm in the appropriate depth to be clean. Installed after the adjustment of resistors R1, bringing the total current is 0.6A or so.
  Made all the components can be installed on the PCB can also be used on thin rubber wood drilling riveting hollow rivets, fitted with components and then wire is good, the location of each component can be configured properly.

Air negative ion generator increased the use of high-voltage corona ion content in the air to improve air quality, can promote good health, known as "air vitamin." Clinical Practice has proved that its respiratory system, circulatory system and neurological diseases such as have secondary effects, which in life and the medical profession to be widely used.
This paper describes an efficient open-negative-ion generator, which uses high-voltage thyristor inverter, suspension-firing pin, the structure simple and effective, safe and reliable. Mains voltage 160-250V can work properly, and the power pole province, only about 1W, so long-term continuous operation.
Work

The negative ion generator circuit shown in Figure 1 ( Click here to download the schematic diagram ). 220V electricity by the VD1, VD2, and R1, R2 of the rectifier, current limiting, one-way pulse-off current control of VS to produce oscillations, the step-up transformer T, after VD3 million volts rectified by the negative pressure, the discharge for air discharge, resulting in ionization, generates negative ions.
Selection and production of components

Wireless microphone on the market everywhere, but without exception, are quartz crystal oscillators or by LC circuits. As we all know, the door has a non-amplification (refers to small-signal conditions) and the inverted phase of the effect, so long as the use of three non-door, end to end, they form a ring oscillator (or five, seven, nine and other odd ; series as much as low frequency), matched with frequency modulation circuit, the same can also be made into a wireless microphone.
  74LS04 is a TTL integrated circuits, there are six single-ended input NAND gate. I used three of them made of a NAND gate oscillator. When the supply voltage is 5V, the oscillation frequency is about 90MHz, the frequency reduces the supply voltage is lowered; power supply voltage increases the frequency also increased. Of course, the oscillation amplitude will also change accordingly, but have little effect. In this way, I used to change the ways to change the supply voltage frequency (that is, to FM). Specific approach is to use an audio amplification ICs BA328 output, as its power supply.
  BA328 is a recording head amplifier circuit, when the signal to compensate for the tape and should be in balance, feet, and indirectly a series RC network, but here is used for linear amplification, so just take a 100kO ~ 130kO resistance can be. BA328 output (foot) should be equal to the voltage pin (supply) voltage of the half, if the supply voltage of 12V, there should be 6V output, if not, adjust the resistance. Another figure in the 1kO resistor is to adjust the magnification and reduce the gain to improve it.
  Speaking against the electret microphone, the output terminal (pin) voltage can be 5.8V to 6.2V between the rapid changes in the feet of this voltage to the 74LS04 FM signal can produce it, and then by the fourth a NAND gate amplification, isolation and sent to the antenna.
  The wireless microphone can also be changed to 6V supply voltage or 1.5V. In addition, its low power output, the reader can increase the level of high frequency amplification in order to improve it.