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, […]
Newly Updated Circuit Projects:
Solid State Relay (SSR) Circuit using Two MOSFETs
SSR or Solid state relays are high power electrical switches that work without involving mechanical contacts, instead they use just a couple of solid state semiconductors like MOSFETs for switching an electrical load, smoothly, and with high efficiency. SSRs can be used for operating high power loads, through a small input trigger voltage with negligible […]
Emergency LED Lamp Circuit with Battery Overcharge Protection
The following LED emergency light with battery over charge protection feature circuit was designed by me in response to the request sent by PP. Main Features In this article I have explained an LED emergency light circuit with advanced features such as, Using Transistors only The following design of the proposed day/night automatic emergency LED […]
Battery Voltage Monitor Circuits using LM324 and LM3915 ICs
The post describes simple battery charge monitor circuits or battery status indicator circuits using 4 LEDs to 10 LEDs, and using ICs like LM324 and LM3915. The first design is a 4 LED voltage monitor circuit using the versatile IC LM324. The idea was requested by Ms. Piyali. Technical Specifications I’ve a project, if you […]
Simple 1.5 V Inductance Meter Circuit
Here a simplest yet quite accurate inductance meter is presented, which can be built within few minutes. Furthermore, the circuit can be powered-up with a single 1.5V cell. However, a frequency meter would be required to work-out the inductance. Designed and Presented by: Abu-Hafss Using Cross-Coupled NPN BJTs The circuit is pretty straight forward wherein, […]
Op Amp Battery Charger Circuits with Auto Cut Off
In this post I have explained a two op amp IC 741 and LM358 based auto cut off battery charger circuits which are not only accurate with its features but also allows a hassle free and quick setting up of its high/low cut-off threshold limits. High current batteries can e also charged using these circuits. […]