Institute Newton C. Braga

Circuit Bench

Programmable Countdown Timer (CB25198E)
We found this circuit in the February 1989 issue of Radio Electronics magazine. The selectors are...
20 Hour Timer with 555 (CB25536E)
This circuit was found in an article about the 555 in the November 1992 Radio Electronics...
1.78 MHz Telephone Transmitter (CB16689E)
This 1992 circuit operates in the range of cordless phones used at the time. The circuit is based...