Here is a simple Tachometer schematic. The basis of the frequency converter circuit-current, which converts the input signal into a proportional current measured pointer device. Deflection milliammeter proportion to the frequency input signal. To install the device on input pin A car should be connected to high voltage wire and pin B – to the… Read More »
This is the schematic diagram of solar powered mobile phone battery charger. The circuit is designed to charge the battery from a source with a lower voltage. Do not use it to charge the battery with the same or lower voltage than the voltage which is generated by the solar panel. For proper operation of… Read More »
This is the schematic diagram of sound activated light or lamp. The lamp or light will be turned on while a loudy sound catch by the microphone (for example: hand clap) How this sound activated light works: The condenser microphone fitted inside a position to catch the sound and generates AC signals, which pass by… Read More »
This two chips AM radio receiver circuit is a tuned radio frequency (TRF) receiver of the standard AM (amplitude modulation) radio with broadcast frequencies at 550kHz-600kHz. This is a simple and easy to build AM radio circuit which only using two integrated circuits (IC). This circuit works with 9V voltage supply, you could use 9V… Read More »
This LAN tester circuit originally designed by Vassilis Stergiopoulos. This LAN tester circuit optionally has two designs. The first design is built based 2 main ICs that are timer IC555 and decade counter 4017. The second design is based microcontroller chip ATtiny2313 (the other kind of microcontroller should be work). The first design circuit (555… Read More »
This is a ultrasonic motion detector (or movement detector) circuit. The circuit claimed has a high movement sensitivity. Even air moving (hot air rising, wind blowing) will trigger it when the trimpot is set near the most sensitive position. The transmitter sends out a steady ultrasonic tone at 40kHz. At this frequency the wavelength is… Read More »
This diagram is the schematic diagram of telephone switcher using relays. This device connects to the telephone line and can be used to remotely control up to 4 relay outputs using a DTMF (tone dialing) telephone. A number of user settings are available to improve the useability and security of the device. The kit comes… Read More »
This circuit is basically a 8W inverter circuit. The circuit continues to be intended to drive an 8W fluorescent lamp from a 12V power supply, utilizing an cheap inverter primarily based on a ZTX652 transistor. The inverter will operate from supplies in the variety of 10V to 16.5V, obtaining efficiencies up to 78% as a… Read More »
This is a logarithmic amplifier circuit based on National operational amplifier LM11C. Unusual frequency compensation provides this logarithmic converter a 100 us time continual from 1 mA down to 100 uA, escalating from 200 us to 200 ms from 10 nA to 10 pA. Optional bias electric current compensation can give 10 pA resolution from… Read More »