tag:blogger.com,1999:blog-71743045689588980362024-03-13T21:18:01.996+07:00Electronics Project Circuit For YouCollection of electronics projects, circuit schematics design, diy hobby projects, printed circuit board softwares for students and hobbyistsUnknownnoreply@blogger.comBlogger87125tag:blogger.com,1999:blog-7174304568958898036.post-1474548455059148992012-01-01T14:38:00.012+07:002012-02-20T09:44:13.732+07:00555 Touch SwitchThis touch switch built based on famous 555 timer IC. When the plate is touched the 555 timer is triggered and the output on pin 3 goes high turning on the LED and the buzzer for a certain period of time. The time that the LED and the buzzer is on is based on the values of the capacitor and resistor connected to pin 6 & 7. The 10M resistor on pin 2 causes the the circuit to be very sensitive Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-7182422656824406482012-01-01T09:29:00.004+07:002012-02-20T09:37:43.216+07:00Maximite Stepper Motor InterfaceThis simple circuit and program listing allows the Maximite microcomputer (SILICON CHIP, March-May 2011) to control a stepper motor. It could be expanded to allow for the control of multiple motors, with four of the Maximite’s external I/O pins used to control each motor with identical driver circuits. A ULN2003 Darlington transistor array (IC1) switches current through the stepper motor’s two Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-40376703196548105952011-10-04T12:42:00.005+07:002011-10-06T12:46:55.492+07:00IR Remote SwitchImagine the convenience of selecting TV channels using your remote and then pointing the same remote to your switchboard to switch on/off the fan or the tubelight. Here is a simple circuit to remotely switch on/off any electrical device through a relay using the normal TV/VCR/VCP/VCD remote control unit. It works up to a distance of about 10 metres. The circuit is built around a 3-pin IR IC Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-71640603051158759922011-10-04T04:47:00.002+07:002011-10-04T04:47:00.240+07:00Infrared Remote for Toy Car Motor ControllerThis add-on circuit enables remote switching on/off of battery-operated toy cars with the help of a TV/video remote control handset operating at 30–40 kHz. When the circuit is energised from a 6V battery, the decade counter CD4017 (IC2), which is configured as a toggle flip-flop, is immediately reset by the power-on-reset combination of capacitor C3 and resistor R6. LED1 connected to pin 3 (Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-79979035578021765032011-10-03T23:54:00.022+07:002011-10-03T23:54:00.428+07:00Gas Leakage Alarm LPG gas leakage detector with audio visual indicator
LPG gas is supplied in pressurized steel cylinders. As this gas is heavier than air, when it leaks from a cylinder it flows along floor and tends to settle in low spots such as a basement. This can cause fire or suffocation if not dealt with.
Here is a circuit that detects the leakage of LPG gas and alerts the user through Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-78919617453377963512011-10-03T20:17:00.018+07:002011-10-03T20:32:17.970+07:00Home Appliance Controller Using TV RemoteSwitch home or industrial appliance On/Off with TV remote control
This circuit is designed to switch on/off any home or industrial appliance by using the TV/DVD remote controller. The circuit can be operated up to a distance of 5-10 metre depending on the remote used. The circuit consists of a step-down transformer X1 (6V-0-6V, 250mA secondary), 5V regulator 7805 (IC1), two 5V, 1 change-overUnknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-30104289853902966732011-08-08T09:39:00.014+07:002011-09-30T09:57:24.426+07:00Bicycle Horn Using Tone Generator KA2411An interesting circuit of a bicycle horn based on a popular, low cost telecom ringer chip is described here. This circuit can be powered using the bicycle dynamo supply and does not require batteries, which need to be replaced frequently. The section comprising diodes (D1 and D2) and capacitors (C1 and C2) forms a half-wave voltage-doubler circuit. The output of the voltage doubler is fed toUnknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-11558193716498816062011-08-06T09:18:00.016+07:002011-09-30T09:35:38.360+07:00Luxurious Toilet Bathroom ControllerSmart controller for your toilet and bathroom. The light and fan will automatic on when someone entere toilet or bathroom and off when no person inside it.
Aged persons in the house and guests often fumble while searching for the toilet and bathroom switches at night. Also, very few of us take care to switch off the lights of toilets/bathrooms after using them. The circuit given here helps Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-85469462207668930802011-08-05T08:56:00.012+07:002011-09-30T09:02:03.273+07:00Random Number Generator GameThis electronic game is simulation of one-arm bandit game. Electronics hobbyists will find it very interesting. When toggle switch S1 is in ‘run’ position, all segments of 7-segment displays (DIS1 through DIS3) will light up. On turning toggle switch S1 from ‘run’ to ‘stop’ position, displayed digits will continue advancing and the final display is unpredictable. Thus the final number Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-13787326514155649522011-08-04T08:41:00.019+07:002011-09-30T08:50:45.269+07:00Audio Source Touch SelectorOften you need to connect output from more than one source (preamplifier) such as tape recorder/player and CD (compact disc) player to audio power amplifier. This needs disconnecting/connecting wires when you want to change the source, which is quite cumbersome and irritating. Here is a circuit that helps you choose between two stereo sources by simple touch of your hand. This circuit is so Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-58009140077056034182011-08-03T08:32:00.002+07:002011-09-30T08:40:11.330+07:00Musical Touch Bell UM66This musical call bell circuit can be operated by just bridging the gap between the touchplates with one’s fingertips. Thus there is no need for a mechanical ‘on’/‘off’ switch because the touch-plates act as a switch. Other features include low cost and low power consumption. The bell can work on 1.5V or 3V, using one or two pencil cells, and can be used in homes and offices. Two Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-76128900347730266232011-08-02T07:21:00.011+07:002011-09-30T07:32:32.222+07:00High / Low Voltage Cutoff With TimerThis inexpensive high / low voltage cutoff circuit can be connected to an air-conditioner/fridge or to any other sophisticated electrical appliance for its protection. Generally, costly voltage stabilizers are used with such appliances for maintaining constant AC voltage. However, due to fluctuations in AC mains supply, a regular ‘click’ sound in the relays is heard. The frequent Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-59953863940278534522011-08-01T06:56:00.002+07:002011-09-30T07:09:57.988+07:00Automatic Heat DetectorThis Automatic Heat Detector circuit uses a complementary pair comprising npn metallic transistor T1 (BC109) and pnp germanium transistor T2 (AC188) to detect heat (due to outbreak of fire, etc) in the vicinity and energise a siren. The collector of transistor T1 is connected to the base of transistor T2, while the collector of transistor T2 is connected to relay RL1. The second part of the Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-33315771926192824522011-07-25T14:39:00.013+07:002011-07-25T14:39:00.565+07:00Simple Alarm SystemThe circuit presented here is a very simple and yet highly effective alarm system for protecting an object. The circuit requires no special devices and can be built using components that you will no doubt be able to find in the junk box. The alarm-triggering element is a simple reed switch. To generate the alarm signal itself any optical or acoustic device that operates on 12 V can be used: Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-91526084361868422652011-07-25T10:27:00.001+07:002011-07-25T10:28:21.285+07:00Video Switch for Intercom System IC 4060Nowadays a lot of intercom units are equipped with video cameras so that you can see as well as hear who is at the door. Unfortunately, the camera lens is perfectly placed to serve as a sort of support point for people during the conversation, with the result that there’s hardly anything left see in the video imagery. One way to solve this problem is to install two cameras on the street sideUnknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-51024016059511937712011-07-19T13:45:00.016+07:002011-07-19T13:45:01.202+07:00Stereo LED Power (VU) Meter
This circuit senses AC audio voltage supplied to the car-radio loudspeakers and displays it as power using a LED bar graph, achieving at the same time an attractive visual effect. It is designed to cover common car-radio output power ranges, but can easily be modified to suit different needs. It is supplied from the 12 V car electrical system and is suitable for classical CC (Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-19780107979788117862011-07-19T08:07:00.004+07:002011-07-19T08:07:00.116+07:00Real RS232 For Laptop/Notebook PCsMany Metex DVMs feature a serial interface (RS232) which enables measured values to be copied to a PC for processing. Although this works just fine with most desktop PCs, problems may arise — as the author found out the hard way — when a laptop PC like the IBM Thinkpad 370C is hooked up to the Metex DVM. The cause of the problems is the limited voltage swing of just ±5V on the 370C’s serial Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-67522798722328662332011-07-19T03:01:00.016+07:002011-07-19T03:01:00.334+07:00Microscope 2.5-D LightingInteresting, surprising as well as scientifically useful visual effects can be obtained by employing colored LEDs instead of the normal lamp fitted in the lighting assembly in a microscope base. Of course, the lamp can be simply replaced by a white LED with appropriate changes in the supply current/voltage etc., but it is more interesting to have three colors available — here, red, green and Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-6233102076735951692011-07-18T23:43:00.019+07:002011-07-18T23:43:00.549+07:00Two Keyboards on one PCThis circuit does the exact opposite of what most of this type of changeover switches attempt to do. Usually a changeover switch is used with two PCs and one keyboard. This version however makes it possible to operate one PC with two keyboards.
K1 is connected to the PC for this purpose while K2 and K3 are connected to two keyboards. The data outputs of the keyboards are high in the idle Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-17603790165329577252011-07-18T20:10:00.000+07:002011-07-18T20:10:03.265+07:00Overheat Detector Alarm LM35At the heart of this over heat detector circuit is a precision integrated temperature sensor type LM35 (IC1), which provides an accurately linear and directly proportional output in mV, over the zero to +155 degrees C temperature range.
The LM35 develops an output voltage of 10 mV/K change in measured temperature. Designed to draw a minimal current of its own, the LM35 has very low self Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-38658875707058470932011-07-18T15:05:00.000+07:002011-07-18T15:05:00.622+07:00DRM Direct Mixer EF95/6AK5This hybrid DRM receiver with a single valve and a single transistor features good large-signal stability. The EP95 (US equivalent: 6AK5) acts as a mixer, with the oscillator signal being injected via the screen grid. The crystal oscillator is built around a single transistor.
The entire circuit operates from a 6-V supply. The receiver achieves a signal-to-noise ratio of up to 24 dBUnknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-17524130658540410812011-07-18T11:18:00.000+07:002011-07-18T11:18:01.211+07:00Converting a DCM MotorWe recently bought a train set made by a renowned company and just couldn’t resist looking inside the locomotive. Although it did have an electronic decoder, the DCM motor was already available 35 (!) years ago. It is most likely that this motor is used due to financial constraints, because Märklin (as you probably guessed) also has a modern 5-pole motor as part of its range. Incidentally, Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-25851628117333921122011-07-16T21:50:00.015+07:002011-07-16T21:50:00.241+07:00Incandescent Lamps Life ExtenderOne way to extend the operating life of incandescent lamps is to reduce the voltage across the lamp by connecting something in series with it. Naturally, a series resistor is the simplest solution, but this produces unnecessary power dissipation. In order to reduce the voltage on a 100-W lamp by approximately 10 V, slightly more than 4 W must be dissipated in the resistor, and that is Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-91725311963771111392011-07-16T18:54:00.009+07:002011-07-16T18:54:00.859+07:00Garden LightingCompletely ‘self-supporting’ garden lamps using solar cells as their energy source are gradually becoming more and more common. How do they actually work? We took one apart to find out. From environmental and technical considerations, buying such a solar-cell garden lamp has a lot to recommend it. It’s a great thing that the energy necessary for the lamp to burn in the evening can be drawn Unknownnoreply@blogger.comtag:blogger.com,1999:blog-7174304568958898036.post-6135837434232976382011-07-16T13:26:00.000+07:002011-07-16T13:26:03.633+07:0050W Audio Amplifier Using IC TDA1562The integrated output amplifier described in this article consists of little more than one integrated circuit. It is intended especially for use in motor vehicles and other battery-operated applications. Although it appears simple and hardly worth looking at, the amplifier can produce an appreciable audio power output. The circuit diagram in Figure 2 emphasizes how few external components Unknownnoreply@blogger.com