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 [...]

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 [...]

RJ45 is used to connect Ethernet port on your computer. There are two configuration: straight and cross. Straight RJ45 cables should be used to connect between computer and device such as switch or hub, and cross RJ45 cables should be used in computer-to-computer connection.  Some hub or switch has the capability to detect the cable [...]

It seems that center tapped transformer with a bridge diode is common solution to provide symmetric supply, but we can actually do it with simpler solution, using a voltage doubler – rectifier diodes. You can see this simple circuit in the figure. The capacitor need to be large because the rectifying is half [...]

Don’t worry if you need a symmetric power supply and you don’t have a center tapped transformer. The circuit below solve your problem. You can see the second bridge diode is powered via capacitor decoupling, so it’s DC isolated. Because it’s DC isolated, we can connect the ground together to form a symmetric supply. [...]

If you need +-15 Volts supply and you have only a standard 12V AC transformer, don’t be hurry to buy a new one with center tap, you can use your old transformer! The schematic diagram of this circuit is shown in the figure below. The voltage before entering the regulator IC [...]