When output voltage functions abnormality (e.g. lost of regulation), it could exceed the rated value. In consequence of that, O.V.P. is triggered to protect end equipments from damage. The protection modes for over voltage are categorized into the following types:
- Shut Off
S.P.S. restarts by manual AC re-power on of after fault condition is removed or over.
- Hiccup Voltage Limiting
Output voltage keeps pulsing ON and OFF repeatedly when protection is activated. The unit automatically recovers when fault condition is cleared
Basically, there are two kinds of O.V.P. detection:
(1) Secondary detection circuit feeds back signal to disable PWM IC from operation.
(2) Short circuiting output by using a Crowbar circuit. This would in turn trigger OLP.