Free Circuit Diagram

This constant current constant voltage  SMPS can be used to efficiently charge a battery. This circuit gives 7.2V at constant voltage mode, and 600 mA at constant current mode. Here is the schematic diagram of the circuit: The mechanism is simple, when the load impedance is high, then the output voltage will be [...]

Current handling capability of a power supply system often needed to be checked. Finding high power rated variable resistor to provide variable load testing might be difficult. There is wire wound type but it’s not always available at your local store, and the price and performance might be disappointing. This variable high power “resistor” uses [...]

This SMPS AC-DC converter gives good efficiency. Test data shows efficiency of 83.2% at 115 Vac input and 6A output current, and 85.4% at 230 Vac input and 6A output current. Moreover, the input voltage range is universal, accommodating 92 to 276 Vac variation with only 24 mV change in the output voltage. Here is [...]

The high durability nature of a light emitting diode (LED) make it suitable for ON/OFF indicator application. Because the limitation on low operating voltage, LEDs are normally applied on low voltage application.  Fortunately, there is a simple method to apply LED indicator for high powerline voltage: reactance of a capacitor can be used to limit [...]

Active power factor correction stabilize the electrical demand of a device to give the best power factor characteristic of many types of loads.  To meet power factor regulation, a low cost solution should be designed. In many application, the need of high DC voltage is usually implemented by a direct rectification of the AC line [...]

This current sensing circuit sense the current at the high side (between positive supply and load). This circuit take the benefit of the microampere supply current and Rail-to-Rail input of the LT1494 op-amp. Here is the schematic diagram of the circuit: Look at the op-amp, the inverting input is connected directly to the [...]