Power Supply | Electronic Project Circuits

Posts Tagged ‘Power supply’

Electronic Fuse for DC Short Circuit Protection by BRX46

This is an electronic fuse that protects the load against short circuit. Relays must be chosen with a voltage value equals to the input voltage. Don’t omit using the 100uF capacitor with appropriate voltage value with respect to the input voltage. If you can’t provide, you can use C106 instead of BRX46.

You can adjust the current with using 10K potentiometer. If you will use the fuse with very high currents, lower the 0R6 5W resistor value (ex. 0R47, 0R33, 0R22 or 0R1). Watt value of the resistor should be increased also.

+8V / -8V dual linear regulators by 78L08 and 79L08

The power supply is a regular split-supply design based on a 78L08 and 79L08 linear regulators. I made use of a 9-0-9 transformer, which was a bit risky (very low headroom voltage for the regulators), but then my dealer didnt have a stock of 12-0-12 transformers. The output of the transformer is rectified and smoothed using 100uF capacitors. The float-voltage measured here for the 9-0-9 transformer was +/- 13V. The unregulated DC is regulated by the 78L08 and 79L08 to give the regulated supply rails for the circuit.

1.2 – 15V 3A adjustable regulated supply by LM1084

This kit provides a variable output power supply ranging from 1.2 to 15 V @ 3 A. It uses Low Dropout Positive Regulator LM1084 in TO220 package for delivering variable output voltage.

* Input – 18 VAC/DC
* Output – variable output from 1.2 ~ 15 V @ 3 A Regulated low ripple DC voltage
* Heatsink for regulator IC
* On board bridge rectifier to convert AC to DC
* LED indication at input of IC
* Zener trimmed band gap reference, current limiting and thermal shutdown (provided by IC feature)
* Power Battery Terminal (PBT) for easy input and output connection
* Onboard PCB mounted Potentiometer (POT) for varying the output voltage
* Filter capacitors for low ripple DC output