nº822

Prototype of sensitive mains voltage detector.

nº821

The frequency of the led ring oscillator can be controlled by shortening the loop on the odd stages.

nº820

Simple light activated JT.

nº819

Simple set-up for checking SMPS PWM controller FSD200.

nº818

Simple sound controlled lamp.

nº817

Simple growing bar with 30 yellow leds, supply 12V.

nº816

Histerese com par diferencial: pontos notáveis.

nº815

Analog lock system with 3 potmeters.
Code set: 243
1) Choose code configuration in the dial panel.
2) Code panel: press correspondent tact-switch while R-trimmer is adjusted until set led is turned off.
3) Repeat step 2 for 2nd and 3rd digits. After 3rd digit is adjusted unlock green led turns on.
4) Unsettle potmeters. System is locked.
Note: knowing 2 digits unlocks the system.

nº814

Mains supplied load controlled by 1 tact-switch with total galvanic isolation.

nº813

Simple flip-flop for mains supplied load is controlled by tact-switches having galvanic isolation and no external power supply on the low voltage side.

nº812

Sound effect "Code accepted or invalid code", supply 2xNiMH.

nº811

Quick setup for converting TDT signal back to analog TV signal (UHF channel 68) to be used with old TV receivers having RF input but no scart input.

Configuração experimental para conversão do sinal TDT para sinal analógico, UHF canal 68, para receptores TV antigos com entrada RF e sem entrada scart.

nº810

Simple twin-T oscillator with 1 bipolar transistor directly driving yellow led, supply 2xNiMH.

nº809

Slow "knight rider" sequence with 2 transistors, supply 9V.

nº808

JT directly driving increasing/decreasing led bar.

nº807

Bilateral led bar controlled by 1 transistor RC oscillator, supply 9V.

nº806

Bargraph with 10 Bi-color red-green leds, supply 9V.