Low frequency pulse therapy device II

Circuit Operation Principle The low-frequency pulse therapy device circuit introduced in this example consists of a time-based integrated circuit IC, transistors Vl, V2, and a pulse transformer T, as shown in Figure 9-20.

The IC and the peripheral low-resistance capacitive component are connected to an astable multivibrator, and the frequency of the output signal can be adjusted by the potentiometer RP1 (the frequency range is adjusted by 0.6-4 Hz).
The transistor V1, the potentiometer RP2 and the resistor R3, and the charging capacitor C4 constitute a voltage source for output voltage regulation.
After the power switch S is turned on, the astable multivibrator oscillates, and the low frequency pulse signal is output from the 3 pin of the lC. The signal is applied to the base of the switching transistor V2 via the capacitor C3 and the light-emitting diode VL, so that the V2 oscillation works (only 0.5 ms is turned on when each pulse arrives), and a pulse high voltage of 220 V is generated on the secondary side of the pulse transformer T (0). Adjustable between -250V). This voltage is transmitted to the human muscle tissue or acupoints through two electrodes (two electrode sheets are fixed on the skin of the human muscle surface, separated by 1-5 cm), so that the muscles can relax or stimulate the acupuncture points, and assist the chronic diseases. Therapeutic effect.
Component selection
Rl-R3 uses 1/4W or l/8W carbon film resistors.
RPl uses a small synthetic carbon film potentiometer without a switch; RP2 uses a small synthetic carbon film potentiometer with a switch (power switch S).
Cl, C3 select polyester capacitor or monolithic capacitor; C2, C4-C6 select aluminum electrolytic capacitor with pressure value of l6V.
Both VDl and VD2 use 1N4001-1N4007 silicon rectifier diodes.
VL selects high brightness LED of φ3mm.
Vl selects BC547B or 3DGl2, C8050 and other types of silicon NPN transistors; V2 uses BC337 or 3DK4 type silicon NPN transistors.
The IC selects the NE555 type time base integrated circuit.
T selects lW, 6V/220V power transformer.
GB uses a 9V laminated battery.