nº931

SW band to MW band frequency converter with 1 transistor, supply 4xNiMH.

nº930

Ganged variable capacitor with reading scale

nº929

Simple lamp flasher controlled by LDR, supply +5V_USB

nº928

Four levels clapper for incandescent lamp; low sensitivity to speech, high sensitivity to clapping, supply 230Vac/50Hz.

nº927

Dimmer for incandescent lamp with 4 levels: OFF, L_min, L_med, L_max; tact-switch operates with total galvanic isolation, supply 230Vac/50Hz.

nº926

Staircase lamp controlled by smartphone ringtone. The ringtone audio signal derived from earphones output activates staircase lamp for the predefined timing. Complete galvanic isolation between TRS plug and circuit hot side is achieved by: 1) using one optocoupler to trigger monostable circuit and 2) A photovoltaic led coupler consisting on the hot side white led voltage regulator coupled to yellow led which supplies energy to the optocoupler audio trigger amplifier.

nº925

Light controlled audio spectral glider, supply 3V

nº924

Audio effect "wah wah", suppy 3V

nº923

Longwave experimental radio receiver with 2 bipolar transistors and loudspeaker output. Operating by night, tuning at 252kHz, Radio Algérie, Chaîne 3, supply 3V

nº922

Two RC resonant active filters select two frequencies: 910Hz and 2KHz.

nº921

Inductance meter 47uH-10mH; reading 1uH/ohm, supply 3V

nº920

Staircase timer opto-switch with about 18 seconds fixed timing, supply 230Vac/50Hz

nº919

Experimental SW(9MHz) regenerative receiver: 2 transistors, tickler coil, tuning capacitor, reaction capacitor, loudspeaker output, supply 9V

nº918

Emitter follower RC phase-shift oscillator

nº917

Beep beep mini alarm with led and 1 bipolar transistor supplied with 1 NiMH battery cell: the audio "joules thief"

nº916

Powerful alarm with 2 bipolar transistors is activated by separating small magnet from oscillator inducance, supply 2xLR03

nº915

Simple portable minimalist reflex radio receiver for MW with 2 bipolar transistors, only tuning control, loudspeaker output, supply 1,5V (1xLR03)

nº914

Led chaser with 18 yellow leds is controlled by single CD4017, 10 states counter, supply 3V

nº913

Simple Colpitts oscillator with MOSFET

nº912

MOSFET phase-lag oscillator