In this post I have explained 4 easy to build, compact simple transformerless power supply circuits. All the circuits presented here are built using capacitive reactance theory for stepping down the input AC mains voltage. All the designs presented here work independently without any transformer, or no transformer. The Transformerless Power Supply Concept As the […]
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Adjustable Switching Power Supply Circuit – 50 V, 2.5 Amps
The explained variable switching power supply circuit is designed around the integrated switch mode power supply controller device Type L4960 from SGS. The main features of this switching regulator can be summarized from the following data: Main Features Input voltage range: 9-50 VDC Output voltage variable from 5 to 40 V. Maximum accessible output current […]
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 […]
How to Calculate Transformerless Power Supply Circuits
In this article I have explained how to calculate resistor and capacitor values in transformerless power supply circuits using simple formulas like ohms law. Analyzing a Capactive Power Supply Before I have explained the formula for calculating and optimizing resistor and capacitor values in a transformerless power supply, it would be important to first summarize […]
High Current Transformerless Power Supply Circuit
The simple configuration of a transformerless power supply circuit presented below is able to provide high current at any assigned fixed voltage level. The idea seems to have solved the problem of deriving high current from capacitive power supplies which earlier seemed a difficult proposition. Introduction I have discussed a few transformerless power supply circuits […]