In this post I have explained 8 easy methods of building touch sensor switch circuits at home, which can be used for switching 220 V appliances ON/OFF with mere finger touch operat ions. The first one is a simple touch sensor switch using a single IC 4017, the second one employs a Schmidt trigger IC, […]
Switch
How MOSFET Works like a Switch
Now in our earlier talks we saw that the N-channel Enhancement-mode MOSFET or e-MOSFET works nicely when we supply it with positive input voltage, so this is very important to remember. This type of MOSFET has very high input resistance, almost close to infinity, and because of that we can use it easily like a […]
Bidirectional Switch
In this post I have explained about MOSFET bidirectional power switches, which can be used for operating a load across two points bidirectionally. This is simply done by connecting two N-channel, or P-channel MOSFETs back to back in series with the specified voltage line. What is a Bidirectional Switch A bidirectional power switch (BPS) is […]
3 Sound Activated Switch Circuits Explained
In this post I have explained 3 simple sound activated relay switch circuits which can used as a module for any system that might be assigned to trigger by detecting some kind of sound pressure level. Or simply applications such as a voice activated alarm security circuit. 1) Circuit Objective Utilizing this basic sound activated […]
LM317 Variable Switch Mode Power Supply (SMPS)
So far in this website we have studied LM317 based linear power supply circuits, here I have explained how an LM317 can be executed as a variable switch mode power or SMPS with zero loss. LM317 as Linear Regulator We all know that an LM317 IC is internally designed to work as a linear voltage […]
How to Repair a Switch-Mode-Power-Supply (SMPS)
In this post we try to diagnose a burnt SMPS circuit and try to troubleshoot and repair the circuit. The shown unit is a cheap readymade Chinese make SMPS circuit. This article is written as per the request made by Mr. Kesava. My SMPS got Burnt The below attachment is 12v 1.3 amps SMPS for […]





