When we work in our workshop, it is necessary to have a power supply that is capable of supplying our circuits in a controlled manner. In this way, we avoid damaging our creations before perfecting them. There are many plans for electrical power supplies, in this article we will be showing you how to make a regulated current source in a simple way and with very accessible materials.
- A 120 V or 220 V transformer depending on our electrical network and a 16 +16 V secondary.
- One DB137 and one 2N3055 transistor.
- Two electrolytic capacitors, one of 3300 uF 25 V and the other of 470 uF 25 V.
- A 0.1 uF 100V capacitor.
- Two 1N5402 rectifier diodes.
- A 15 V 400 mW Zener diode.
- A 50K potentiometer.
- Two resistors, one of 270 Ω 1W and the other of 100 Ω 1W.
Assembling our regulated power supply
Assembling our regulated current source will be quite simple, we must first place the transformer on our printed circuit board and then connect it to the diodes in a parallel arrangement.
Next, we make parallel connections to the capacitor, the resistor, the Zener diode and the transistors. Finally, we make a connection to the other resistor and the remaining capacitors and then, we place the outputs that we will connect to the contacts of the equipment that we are going to supply with energy. The assembly of this electronic design can be better visualised in the electrical circuit diagram below:
Once the assembly is complete, we can carry out various tests by connecting our controlled source to different circuits that require power. We must remember that this device is capable of supplying from 0 to 15 V of current and up to 2 amps.
One of the points to bear in mind when making our circuit is that the 2N3055 transistor must be mounted on a good quality heatsink.
Also, it should be noted that this circuit is not designed to withstand overloads, so if you plan to use loads greater than 2 amps it is advisable to place a 2 amp fuse in series with the 2N3055 transistor.