Free Circuit Diagram

This power factor controller accept voltage from 90 to 268 Vac,  that’s why we call it power factor controller with universal input, since any standards of mains supply  in almost any country would fall within that range. This power factor controller is capable of handling up to 450W load. Here is the schematic diagram of [...]

I some cases, a differential input is needed for voltage measurement. Using the only one operational amplifier, you can build an adapter to provide a floating input for your ground-referenced  voltmeter. Use 1% tolerance metal film resistor for R1 and R2.  Adjust VR1 to give zero voltage output when the input probe is [...]

This is an ultra high input impedance AC unity gain amplifier circuit. This circuit is used to get unity gain from ultra high input impedance AC. Here is the circuit: Because we can’t reduce input capacitance of this circuit, so we use the 2N4416 which has low capacitance. It is operated as a [...]

This is a HI-FI tone control circuit with high Z input. This circuit is used to control HI-FI tone. Here is the circuit: To buffer op-amp operated feedback type tone control circuit, this circuit uses 2N3684 JFET. The 2N3684 JFET is implemented on this circuit because it has low noise characteristics and provides [...]

In the simplest form, current to voltage converter can be implemented as simple as one resistor,  since a voltage is developed when an electrical current flow against a resistance. The problem is that the resistance always affect the current by  decreasing the current flow, and the current to voltage conversion is not accurate. In some [...]

Balanced input has three connections, ground, positive signal, and negative signal. When we trace the signal using oscilloscope, if we take the ground as the reference, then the negative signal and the positive signal has similar shape but with inverted polarity. If we measure the signal between positive and negative output, the we have two [...]