nº886

Experimental alarm with 5 yellow leds and 1 bipolar transistor, supply 12V.

nº885

Beep-beep alarm with 1 bipolar transistor and 1 yellow led, supply 2xNiMH.

nº884

Smart cooling fan. Forced air flows to the side where temperature is higher, supply 12V.

nº883

Simple metal detector with 1 transistor operating in the MW radio band, supply 2xNiMH.

nº882

Incandescent lamp automatic fading up and down with RC oscillator, supply 230Vac/50Hz.

nº881

RLC joules thief with photocell by led light sensing.

nº880

Simple 2kHz beep-beep alarm with 1 bipolar transistor, supply 2xNiMH.

nº879

Simple mains supplied latch switch with single led-led photo interrupter.

nº878

Resistors cube equivalent resistance.

nº877

Simple white led bar(2x3) with photocell feature by rectifier diode light sensing, supply 3xNiMH.

nº876

Combined led bar and sound effect with 1 transistor, supply 12V

nº875

Beep-Beep alarm with 1 NE555N, supply 4,5V