Archive for July, 2008
Logic probe tester
Logic testers are simple but very helpful devices in testing digital circuits. A logic probe can be designed in many different ways. In this particular design, a combination of discrete and TTL logic components is applied to test different logic levels. This logic tester can test and display three different logic levels: the “0″ and [...]
1-chip 40 watt amplifier
This is a compact, easy to build amplifier that uses one IC only but delivers 40 watts of audio power. It is ideal for amplifying audio from your mobile CD player or iPod. The chip being used here is the TDA1514 originally brought to the market by Phillips/Valvo. The best characteristics of this chip is [...]
Headphone amplifier
Typically, a headphone is connected to the loudspeaker output of the final amplifier stages through a voltage divider circuit. However, this simple design has two distinct disadvantages. Firstly, the headphone volume cannot be varied independently from the main speaker when the main speaker is switched on at the same time. Secondly, the voltage divider circuit [...]
