MUSCULAR BIO STIMULATOR

Working Of The Circuit

IC1 generates 150µSec. pulses at about 80Hz frequency. Q1 acts as a buffer and Q2 inverts the polarity of the pulses and drives the Transformer. The amplitude of the output pulses is set by P1 and approximately displayed by the brightness of LED D1. D2 protects Q2 against high voltage peaks generated by T1 inductance during switching.

Components Used

P1______________4K7 Linear Potentiometer

R1____________180K 1/4W Resistor
R2______________1K8 1/4W Resistor (see Notes)
R3______________2K2 1/4W Resistor
R4____________100R 1/4W Resistor

C1____________100nF 63V Polyester Capacitor
C2____________100µF 25V Electrolytic Capacitor

D1______________LED Red 5mm.
D2___________1N4007 1000V 1A Diode

Q1,Q2_________BC327 45V 800mA PNP Transistors

IC1____________7555 or TS555CN CMos Timer IC

T1_____________220V Primary, 12V Secondary 1.2VA Mains Transformer

SW1____________SPST Switch (Ganged with P1)

B1_____________3V Battery (two 1.5V AA or AAA cells in series etc.)

Notes

T1 is a small mains transformer 220 to 12V @ 100 or 150mA. It must be reverse connected i.e. the 12V secondary winding across Q2 Collector and negative ground, and the 220V primary winding to output electrodes.

Output voltage is about 60V positive and 150V negative but output current is so small that there is no electric-shock danger.

In any case P1 should be operated by the “patient”, starting with the knob fully counter-clockwise, then rotating it slowly clockwise until the LED starts to illuminate. Stop rotating the knob when a light itch sensation is perceived.

Best knob position is usually near the center of its range.

In some cases a greater pulse duration can be more effective in cellulite treatment. Try changing R2 to 5K6 or 10K maximum: stronger pulses will be easily perceived and the LED will shine more brightly.

Electrodes can be obtained by small metal plates connected to the output of the circuit via usual electric wire and can be taped to the skin. In some cases, moistening them with little water has proven useful.

SW1 should be ganged to P1 to avoid abrupt voltage peaks on the “patient’s” body at switch-on, but a stand alone SPST switch will work quite well, provided you remember to set P1 knob fully counter-clockwise at switch-on.

Current drawing of this circuit is about 1mA @ 3V DC .

Some commercial sets have four, six or eight output electrodes.

To obtain this you can retain the part of the circuit comprising IC1, R1, R2, C1, C2, SW1 and B1.

Other parts in the diagram (i.e. P1, R3, R4, D1, D2, Q2 & T1) can be doubled, trebled or quadrupled.

Added potentiometers and R3 series resistors must be wired in parallel and all connected across Emitter of Q1 and positive supply.

Commercial sets have frequently a built-in 30 minutes timer. For this purpose you can use the Timed Beeper.