nº794

Multipoint led opto latch, supply 4xNiMH.

nº793

Simple latch with 1 transistor operated by a single tact-switch, supply 2xNiMH.

nº792

Two Colpitts oscillators beating at the same frequency make a sensitive metal detector. Two adjustments: sensitivity and audio volume. Supply 2xNiMH.
Detector de metais por batimento de dois osciladores Colpitts. Dois ajustes: sensibilidade e volume. Alimentação 2xNiMH.

nº791

Blinking a white led with RLC "Joules Thief".
Pisca-pisca com led branco baseado no "Ladrão de Joules" RLC.

nº790

Non-volatile opto latch, supply 230Vac/50Hz.

nº789

Minimalist free energy led flasher with 2 bipolar transistors. Flashes every 12 seconds approximately.

nº788

Basic "Joules Thief" with coupled inductors drives white led and operates intermittently.

nº787

Growing bar with 14 white leds based on bargraph circuit, supply 2xNiMH.

nº786

Light controlled bargraph with 1 transistor, supply 9V.

nº785

Simple led chaser, supply 2xNiMH.

nº784

RLC "Joules Thief" with violet led.

nº783

Mains supplied bargraph with 10 white leds.

nº782

Simple bargraph with 1 transistor, supply 24V.

nº781

Capacitive power supply with symmetrical output voltages.
Output +5Vdc (current 0 to 70mAdc)
Output -5Vdc (current 0 to 70mAdc)
Regulators input voltage with open load = 35Vdc.
The current through the simulated bipolar capacitors should be kept balanced.

nº780

Simple RLC JT: the resistor is not in the path of the inductor.

nº779

Very simple bargraph with 12 leds; 1 limiter resistor, supply 24V.

nº778

Sound effect "Firework", supply 9V.
Efeito sonoro "Fogo de artifício", alimentação 9V.

nº777

Simple SCR bargraph with 5 stages; each stage drives a 50W bulb; supply 230Vac/50Hz.

nº776

Led flasher running at 1,2V/300nA.(average)