Free Circuit Diagram

High voltage current sensing/monitoring can be designed using LTC6101 op-amp. The following current sensing circuit is capable of measuring electrical current in 500 volts system. Here is the schematic diagram of the circuit: Two external Mosfets is added to hold off the voltage, allows the LTC6101 to be connected to a very high [...]

This voltage-controlled oscillator circuit is very compact and has a good linearity. The author said that the precision could be better than 0.01% If this circuit is properly constructed. Moreover, this circuit gives three different output waveforms: square, triangle, and sawtooth. This three waveform is important for music synthesizer and measurement [...]

We  can make a simple touch switch using only two inverter gates, two resistors, and two capacitors. The schematic diagram of the circuit is shown in the figure below. At power up, the output (of U1A) will be high, and the inverting output will be low because U1A gate will be triggered to ground level [...]

Many efforts has been made to make simpler circuit, and here is one result, a very simple touch switch.  You can build up to 6 similar circuit using only one 4050 chip. If you touch the “on” pad, the output will be on on remains on until you or some one the “off” pad. Here [...]

Using VFC110 chip, we can build a high frequency voltage-to-frequency converter. The features of this chip include the capability of high frequency operation, disable function, and an on-board precision 5V reference. This precision reference can be used to provide reference for offsetting the VFC transfer function, as well as provide transducer or bridge excitation. As [...]

Thermoelectric cooler (TEC) or Peltier cooler is becoming popular because of its robustness and maintenance free characteristic. Here is one example of a linear thermoelectric cooler (TEC) driver circuit. This driver  is capable of delivering ±2A into a TEC. This circuit operates on a single +5V supply and drives the TEC in the most preferred [...]