nº864

Mains supplied doorbell with 4 components is activated with smartphone led lantern.

nº863

Prototype of simple capacitance meter for oscilloscope. Measured capacitor is 68pF. Oscilloscope time base is 20uS/div.

nº862

Prototype of car turn light with 5 leds, supply 12V.

nº861

Experimental car turn light indicator with 5 yellow leds and 1 transistor, supply 12V.

nº860

Experimental LW/MW TRF audion receiver with 2 bipolar transistors and tuning with varicap diode, supply 9V.

nº859

Simple 12V/5V-100mA self-oscillating buck converter with 1 transistor (switch) and 1 optocoupler. (PWM control)

nº858

Simple BTL class A amplifier based on dual op-amp LM358N drives 110 Ohm loudspeaker with 1.1Vpp sinewave under 2xNiMH power supply.

nº857

Complete experimental MW radio receiver based on dual op-amp LM358N. Envelope detector wtih OA5 Ge diode, 2mts wire antenna + PE connection; supply 2xNiMH

nº856

Simple thermometer with 1 transistor + 1 resistor + 1 trimmer potmeter, supply 2xNiMH