Every home probably has more than one power supply (charger) from various cell phone models lying around. All of them have an output voltage of 5 V. Naturally, it is possible to use such a source in the household, but sometimes there are not as many purposes as there are such sources with the same voltage. Is it possible to somehow change the voltage of this block? Then there would be more opportunities to use it.
In fact, this is quite simple to do, since all phone chargers, plus or minus, have the same circuit.
How to change the block voltage?
The output voltage can not only be reduced, but also increased within 3-15 V. And first, I’ll tell you how. On the board of each switching power supply, mainly in the center, there is a transformer. Visually, it divides the high-voltage part of the block and the low-voltage part. These parts are galvanically isolated, but have feedback through an optocoupler. On the low-voltage part of the board in the optocoupler circuit there is a zener diode, which is responsible for the output voltage level.
If you need to lower the voltage to 3 V, you can simply replace the zener diode and use it, but if you increase it, then you will need to replace the output filter capacitor with another one with a higher voltage.
I think you understand the concept of making changes. Let's get down to business.
Details
To change the voltage, specifically in this source, you will need the following names of parts:- Zener diode 12 V.
- Capacitor 470 uF 25 V.
We increase the voltage of a pulse source with our own hands
We open the case. We find a zener diode. It is always located in the low voltage part of the block.
There is also a filter capacitor nearby.
You can first plug the unit into the network and check it, but of course it’s better to do this in advance while the lid is closed.
We solder the zener diode and capacitor.
We solder new ones instead. The most important thing is not to make a mistake with the polarity.
Once everything is ready, you can check it.
The values turned out to be slightly overestimated. You can try to select a zener diode for a lower voltage, but for this block it will do. Since where it will be used, an excess of 1-2 Volts is not at all critical.
