Electronic massager II

The electronic massager introduced in this example uses a small DC motor as the power to drive two large rollers (wrapped with a flannel cover) to rotate and a plurality of small rollers to rotate around the axis, and the trajectory when the large wheel is rotated relative to the inclined surface of the wheel Changes, the formation of similar hand kneading, squeezing, massage and other massage actions, stimulate the body's reflex zone, to achieve the effect of adjuvant therapy.
Circuit Operation Principle The electronic massager circuit consists of an AC voltage regulator circuit and a rectifier commutation circuit, as shown in Figure 9-35.

AC voltage regulating circuit resistor Rl-R4, potentiometer RP, inductor L, capacitor Cl, C2, bidirectional diode VD and thyristor VT. C2 and R4 form the protection circuit of VT.
The rectification commutation circuit is composed of a diode VD1-VD4, a commutation control switch S2, a capacitor C3 and a motor M.
Turn on the power switch Sl, the AC 220V voltage is charged by R1-R3 and RP after partial pressure, and the other channel is rectified by VDl-VD4 to generate the pulsating DC voltage as the working power of M. When the voltage across Cl is charged to a certain value, VD is turned on, so that VT is triggered to conduct, and M is energized.
Adjusting the resistance of RP can change the charging time constant of Cl, change the average conduction time of VT, change the output AC voltage value, and change the rotation speed of M.
S2 is a forward/reverse scroll control switch. When S2 is placed in the "forward" position, M rotates clockwise; when S2 is placed in the "reverse question" position, M rotates counterclockwise.
Component selection
Rl-R4 uses 1/4W metal film resistors.
The RP uses a synthetic carbon film potentiometer with a switch (S1).
Cl and C3 use a polyester capacitor or CBB capacitor with a withstand voltage of 400V; C2 uses a CBB capacitor with a withstand voltage of 630V.
L is made of 5-8 turns on the I-shaped core with an enameled wire of about φ1.2 mm.
VDl-VD4 selects 1N4007 silicon rectifier diode for use.
V selects DB3 or C644 type bidirectional diode.
VT selects 3A, 600V bidirectional crystal tube, such as TLC336A and other models.
S2 selects KB88 type 5A, 250V bipolar double position toggle switch.
M selects ZY8-54S type 20-40W series excitation motor.