Low frequency pulse therapy device

This example introduces a low-frequency pulse therapy device made of discrete components, which has the characteristics of simple circuit and easy production.
Circuit Operation Principle The low-frequency pulse therapy device circuit consists of an RC phase-shifting oscillator, a buffer amplifier circuit, and an output circuit, as shown in Figure 9-19.

The RC phase shift oscillator circuit is composed of resistors R1-R6, capacitors Cl-C3, C5, and transistor V1, and has an oscillation frequency of 2.5-4.5 Hz.
The buffer amplifying circuit is composed of the emitter amplifying tube V2 and the resistors R7-R9, capacitors C1, C7 and the like.
The output circuit is composed of an output amplifying tube V3 and a step-up transformer T, a potentiometer RP, a resistor R10 and the like.
After the oscillation pulse generated by the RC phase shift oscillator is subjected to V2, V3 amplification and T boost processing, a low frequency pulse voltage (greater than 80 V) is generated on the secondary winding W3 of T. After the pulse voltage is adjusted by RP, the two electrode pieces externally connected to the socket XS are applied to the patient's acupoints to stimulate the meridians of the human body, thereby achieving treatment of certain diseases (such as frozen shoulder, cervical spondylosis, lumbar muscle strain, etc.) the goal of.
Component selection
Rl-Rll selects 1/4W carbon film resistor or metal film resistor for use.
The RP uses a small synthetic carbon film potentiometer with a switch.
Cl-C3 selects polyester capacitor or monolithic capacitor; C4-C8 selects aluminum electric capacitor with pressure resistance greater than 16V.
VL selects red LED of φ3mm for use.
Vl-V3 selects silicon NPN transistor, wherein Vl and V2 select S9013, S9014 or 3DG6, 3DG201, and V3 selects C8050 or 3DGl2, 3DGl30.
T can be replaced by an input transformer in a semiconductor radio.