Free Circuit Diagram

This PWM motor control circuit provides many controls for DC motor. You can control the DC motor to rotate forward, reverse, or break until it stops. Here is the schematic diagram of the circuit:

The circuit uses MOSFETS bridge to drive the motor, controlled by some logic gates and small bipolar transistors. The motor voltage can [...]

This circuit is conventional “Pierce” type oscillator that uses a JFET. The circuit uses fundamental mode crystals. It has decent performance and reliability if we use a low noise JFET.

The feedback is controlled by the C1 Capacitance from drain to ground. Adjusting the frequency can be done by adjusting a shunt capacitance C2 across the [...]

By detecting a voltage drop in resistor connected in series with the battery, we can measure the current flowing in or out  of the battery. A simple differential amplifier do that, but we need both positive supply and negative supply to sense the current in both direction,  the current when charging and discharging the battery. [...]

This circuit is a simple crystal oscillator that can be operated in overtone mode. Overtone mode permit the operation at higher frequency than specified by the crystal.

The circuit uses a grounded base amplifier configuration, and place the crystal as a series resonator. The transistor Q1 is biased in the active region as an amplifier.  L1C1 [...]

Sine wave oscillator can be implemented using Wien-Bridge oscillator like in our previous sine wave oscillator circuit, but now we present another method of generating sine wave signal. Using phase shifter, we can build a simple sine wave generator, as shown in the schematic diagram below:

Sine wave oscillator using phase shifter has lower distortion than [...]

The LM4610 uses DC  signal to control the tone (bass/treble), volume, and balance circuit.   The advantages of using DC control is that you can use a mono potentiometer to control both channel, even you can use a DC signal generated from a DAC, so you can control the sound using microcontroller or microprocessor. This circuit [...]