| 摘要 |
PURPOSE:To previously prevent elements from being damaged on short-circuiting the output end, by coupling the DC bias power source of an inverter with the output end optically using a photocoupler, and by supervising the presence of the short circuit of the output end automatically. CONSTITUTION:While a luminescent element 11 is provided for an output end and radiates with output voltage, a light receiver element 12 is inserted into the DC bias power source 8 of an inverter and is optically coupled with the luminescent element 11 provided for the output end. While specified voltage for output is generated at the output end, the luminescent element 11 radiates, and the light receiver element 12 for receiving the light is conducted, and so the voltage of the DC bias power source 8 can be fed to the base of each transis tor 7, 7'. When the output end is kept in a short-circuiting state, the luminescent element 11 gets not to radiate. Accordingly, the light receiver element 12 gets to be non-conductive, and the DC bias gets not to be fed to the base of each transistor 7, 7' of the inverter 2, and the oscillation stops. |
