Category Archives: Misc



Telephone Amplifier using LM386

The following diagram is the circuit diagram of telephone amplifier, build based small amplifier IC LM386. This is a easy build telephone amplifier There is no extra electrical power supply required to power up the telephone amplifier circuit, as it draws power from the telephone line itself. The amplifier will supply fairly very good volume… Read More »

Load Cell Amplifier

I’ve found some interesting schematic of load cell amplifier. As we know, load cell amplifier is pretty expensive with fair price range of 100-300 USD. You may built your own load cell amplifier to get the lower cost. Here the two scheme diagram of load cell amplifier circuit: Load Cell Amplifier using AMP04: source: http://cgi.ebay.com/Load-Cell-Amplifier-Improved-Better-Stability-New-/350451149452

Solid State Relay

This is the circuit diagram of solid state relay. In reality, it is not a relay after all. There’s no ‘relay’ found, just the electronics circuit which does the switching. It operates a similar way as a relay; it is possible to use a low voltage to switch a higher voltage or better than ordinary… Read More »

12V Lead-Acid Battery Monitor

This easy circuit makes it possible to monitor the charging process to a higher level. Final adjustsments are simple and easy and the only device required is a digital voltmeter for the important accuracy and reliability. Connect an input voltage of 12.65 volt between the positive and negative poles and adjust the 10K trimmer potentiometer until Led 10 lights up.

Adjustable Sine/Square Wave Oscillator

The following scheme diagram is the circuit diagram of simple easily tuned / adjustable sine and square wave oscillator. With this circuit you can easily generate sine/square wave which can be adjusted both the frequency and amplitude. The circuit uses IC LM101A, a general purpose operational amplifier (op-amp) and IC LM111, a high-speed voltage comparator… Read More »