This simple 220V power interface is intended as an interface for monitoring electric equipments and devices using a computer. The interface only senses whether the device being monitored is turned on or off. The most important aspect of the circuit is the galvanic isolation between the AC main line being monitored and the interface to the computer. This is done with the use of the optocoupler IC TIL111 but a suitable replacement can be used too.

This is a compact adjustable power supply that delivers a stable voltage and currents up to 3 amperes. The circuit is very conventional and its voltage output can be varied from 1.25 volts to 25 volts.
The main module is the LM350 IC which integrates a voltage regulator and a power stage. It also has a built-in overload protection which activates at 30 watts of power dissipation. The voltage output is set by connecting the “adj” pin of the IC to the voltage divider made of R1 and P1. The output voltage can be calculated using the following formula:

This power supply circuit is highly stabilized that its output voltage will drop only 0.005% even though the load changes from 0 to 100%. Another excellent capability is that the output voltage will change only by 0.01% if the input voltage fluctuates. The capability if the circuit to be adjusted from 0.1V up to 50V is due to the application of opamp IC CA3130 in the circuit. Transistor T4 raises the output voltage to higher level, and at the same time it separates the lower level opamp from the high level of the output voltage. The reference voltage is supplied by IC1. It is a temperature compensated transistor array with 5 transistors. Four of these transistors are used as reference diodes and the fifth one sets the output impedance of the reference source.

This general purpose power supply can e used for supply output voltages from 1 to 35V. The line transformer should be selected to give about 1.4 times the desired output voltage from the positive side of filter capacitor C1 to ground. Potentiometer R2 sets the output voltage to the desired value by adjusting the reference input.

The GPMP0901 12V, 12 Amp switching power supply is great for a wide range of applications as it is capable of maintaining 12 amps output current at 12V DC.
The ElectriFly 12 Amp switching power supplies accepts power from a 110V AC source. This is a “switching” power supply as opposed to a linear power supply which employs a high frequency switch-mode design to convert 110V AC input to a fi xed 13.8V DC output. This stateof-the-art technology allows the power supply to operate entirely without a big, heavy internal transformer and results in a very small, and lightweight device that can deliver a tremendous amount of power. This technology also generates highly effi cient and clean DC output. This is especially valuable today as many R/C chargers utilize peak detection designs which are very sensitive and demand the cleanest power sources possible in order to maintain error-free operation.