In this article I have explained how to make a cheap yet effective mains operated AC overload and over-current protector circuit using very ordinary discrete components. Introduction I have published a few mains voltage stabilizer circuits in this blog, these units are designed and intended for safeguarding the connected appliances at their outputs. However these […]
Archives for 2012
Surge Protected Cheap Transformerless Hi-Watt LED Driver Circuit
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 […]
Thermostat Delay Relay Timer Circuit
The circuit given below describes a time delay relay system which is used for keeping a hot air blower working under a specifically programmed timing sequence. The idea was requested by Mr. Doug Shadix, I have explained more: Technical Specifications Hi Swagatam,Looks like you know your stuff when it comes to these timer circuits, this one […]
Motor Protection Circuits – Over Voltage, Over Heat, Over Current
In this post I have explained a few DC motor protection circuit from harmful conditions like over voltage and under voltage situations, over current, overload etc.. DC motor failures are commonly experienced by many of the users, especially in places where the relevant motor is run for many hours a day. Replacing motor parts or […]
Vibration Meter Circuit for Detecting Vibration Strength
In this article I have explained a couple of simple vibration meter circuits which can detect and measure the strength of mechanical vibrations. Video Clip demonstrating the Vibration meter working The proposed circuits are built using transistors and also with an IC for getting a bar graph LED sequence for the level indications. The bar […]
Simple 12V, 1A SMPS Circuit
In the following content I have explained two simple 12V, 1 Amp switch mode power supply (SMPS) circuit using the very reliable VIPerXX IC from ST microelectronics. With the advent of modern ICs and circuits, the age old iron transformer type of power supply are surely becoming obsolete. Today power supplies are much compact, smaller […]





