Oscilador de deslocamento de fase com malha RL e 1 transístor bipolar, alimentação 2xNiMH

Simple RL phase-shift oscillator with one bipolar transistor produces pure sinewave signal in the audio frequency range, supply 2xNiMH 

Sirene com 1 transístor e led pisca-pisca, alimentação mínima 0,4V

The "Joules Thief Siren" with blinking led, minimum supply 0,4V

Led pisca-pisca vermelho alimentado por pilha NiMH com auxílio do "ladrão de Joules"

A flashing led would normally not operate when supplied by a tired NiMH battery. However it becomes possible with the help of the "Joules thief" converter.

Relé de controlo da tensão de rede monofásica 230Vac/50Hz

                                                 Single-phase voltage control relay switches-off the load, including its own supply, whenever mains input voltage changes more than 10%. Manual restart. Simple application for the window comparator. 24Vdc relay is used.



Ligar led branco com 1 transístor, sem indutâncias e alimentação 1,5V

 

Turn-on white led with 1 bipolar transístor, without inductive components and 1,5V supply voltage.

Multivibrador astável para 2 leds amarelos com temporização por condensadores de 470pF



Sequencial com 4 leds RGB, alimentação 2xNiMH



Flashes de led branco; circuito simples com LDR, alimentação 2xNiMH



 



Barra com 4 leds RGB, alimentação 2xNiMH

Indicador sonoro e luminoso de intensidade luminosa com 1 led, alimentação 2xNiMH

 

Simple 3 transistor light controlled multivibrator.

More light detected by the led increases led flashing and speaker "plop" frequency.

Receptor rádio reflex para a banda AM com 1 transístor e saída em altifalante, alimentação 9V

Simple reflex radio receiver for the AM band. Uses only one bipolar transistor. Sound output by loudspeaker. Ferrite antenna not enough. About 5m wire antenna and earth connection are necessary for acceptable sound quality. Selectivity is good. Supply 9V.

Flashes com led RGB alimentados por 1 pilha de 1,5V

RGB led flashes supplied by 1 LR6 battery. 3 transistors only. Red colour is just before green and blue flashes.

Desmultiplexador de cores para led RGB

Simple colour demultiplexer for RGB led.