A transcutaneous nerve stimulator uses a control circuit to detect a transformer inductive current of a boost circuit and compares a sensing voltage generated by the transformer inductive current with a limiting voltage, such that the operation of a switch element in the boost circuit can be determined so as to turn on or off the boost conversion operation of the transformer. Thereby, the boost circuit can generate sufficient working voltage with the lowest power consumption of the transformer. In addition, a conversion circuit can be utilized to convert the working voltage to a simulation signal outputted at a positive-negative cycle for eliminating charge accumulation in a human body, such that the transcutaneous nerve stimulator can be directly modulated to a particular electrotherapy frequency via the conversion circuit.一種經皮神經刺激器,以一控制電路感測一升壓電路的變壓器電感電流,將變壓器電感電流產生之感測電壓和一限定電壓作比較,即可決定升壓電路中開關元件之運作,以導通或截止變壓器之升壓轉換運作,使升壓電路可以最低的變壓器功率消耗即產生足夠的工作電壓,並且利用一轉換電路達到將工作電壓以正、負半週輸出之刺激訊號消除人體電荷累積,使該經皮神經刺激器透過轉換電路直接調變所需特定電療頻率。1‧‧‧經皮神經刺激器10‧‧‧控制電路12‧‧‧比較器14‧‧‧誤差放大器20‧‧‧時序電路22‧‧‧雙穩態電路30‧‧‧升壓電路32‧‧‧變壓器322‧‧‧一次側線圈324‧‧‧二次側線圈34‧‧‧穩壓電路40‧‧‧轉換電路402‧‧‧直流端組404‧‧‧輸出端組C‧‧‧電容CK‧‧‧導通訊號Q‧‧‧真值端Qt‧‧‧開關元件L‧‧‧電感R‧‧‧感測電阻Vcc‧‧‧電源Ve‧‧‧限定電壓Vout‧‧‧工作電壓VRb‧‧‧刺激訊號Vs‧‧‧感測電壓
