Electronic anti-asthma circuit

As the saying goes, "Surgery cannot cure ringworm, and internal medicine cannot cure asthma." This example introduces an electronic antiasthmatic device that generates high-voltage stimulation pulses that
can serve as auxiliary treatment for patients with cough and asthma.
    (1) Circuit composition The anti-asthmatic circuit consists of a self-excited multivibrator, a buffer amplifier circuit and a high-voltage generating circuit, as shown in Figure 24-2.
    The self-excited multivibrator consists of transistors VT1, VT2, capacitors c1, c2 and resistor R. —R. etc. composition.
    The buffer amplifier circuit consists of emitter amplifier tube VT3, bias resistor W, R. It is composed of coupling capacitors C and C4.
    The high voltage generating circuit is composed of potentiometer RP, resistor Rs, amplifier output tube VT4, auto-coupling step-up transformer T and output plug XS.
    (2) Working principle The self-excited multivibrator generates an oscillation signal with a frequency of about 500Hz.
After being amplified by VT3 and VT4 and boosted by transformer T, a high-voltage pulse 1 voltage greater than iocf\ is output from the socket xS. The pulse voltage is added to the
Tiantu point (in the middle depression of the upper edge of the thoracic notch when sitting with the head tilted up when sitting) and Taizhui point (in the middle of the thoracic notch when sitting or sitting with the head down) through two external electrode pads. 7 cervical vertebrae), adjusting
the resistance of the potentiometer RI' can change the amplitude of the output high-voltage pulse voltage, thereby adjusting the intensity of the electrical pulse.