The increased number of complaints from the readers regarding burning LEDs associated with my earlier posted transformerless 1 watt LED driver circuit, compelled me to solve the issue once for all. The power supply section of the circuit discussed here remains exactly identical to the previous configuration, except the inclusion of the “switch ON delay […]
Power Supply Circuits
Transformerless Relay Driver Stage
In this post I have explained an enhanced transformerles power supply circuit design which consists a well stabilized and regulated DC stage along with a relay driver stage which operates through an external pulse. he idea was suggested by Mr. Reza. Technical Specifications Reza: Dear Sir, I have a problem with one Circuit regarding converting […]
LM317 with Outboard Current Boost Circuit
The popular LM317 voltage regulator IC is designed to deliver not more than 1.5 amps, however by adding an outboard current boost transistor to the circuit it becomes possible to upgrade the regulator circuit to handle much higher currents, and upto any desired levels. You might have already come across the 78XX fixed voltage regulator […]
IC 741 Power Supply Circuits
In this post I have explained how to make simple yet fully stabilized and regulated, variable power supply circuits using the IC 741 op amp. Three versions of the 741 power supplies are I have explained below: Simple Variable IC 741 Power Supply The first figure below exhibits a IC 741 based simple variable voltage […]
3 Solid-State Single IC 220V Adjustable Power Supply Circuits
These AC to DC power supplies use a single chip to convert mains 220 V or 120 V input AC into 12 V or 5 V DC without depending on a transformer. Three simple yet efficient 220V single chip based solid state transformerless adjustable solid-state power supply circuits are discussed here. The first one works […]
Simple Crowbar Circuits for Over-voltage Protection
A handful of simple DC over voltage protector crowbar circuits are discussed in this article. I have explained the working of each crowbar circuit through the following explanation. What is Crowbar Circuit If you are wondering what is a crowbar circuit, the definition is simple. It is a circuit network where a transistor or an […]