| 摘要 |
<p>The source and control circuit allows the practitioner to optimise the position, current level and frequency of the injected current in acupuncture, rheumatic treatment etc. Minimum electrical resistance in the treated area is indicated once found by a pair of LEDs. Similarly, a set current level is indicated as attained, by a second pair of LED's, the actual current level being displayed by a centre zero meter. The circuit is powered by rechargeable cells and uses an amplifier connected into a bridge as a comparator measuring the skin resistance, one arm of the bridge including a potentiometer. A second amplifier works as a variable frequency oscillator in the 1HZ to 300Hz range. Two further amplifiers allow the generated waveform to be varied about a null level by use of a potentiometer between a positive and negative supply.</p> |
