Moreover, for gadgets such as amplifiers which are home built this protection device could prove to be very effective and useful.
Normally all sophisticated gadgets today incorporate an in built short circuit protector arrangement, yet still adding a more comprehensive external protection device could only benefit the connected system. My amplifier runs at +/- 36 V and I really needed it as I live near a village where there is lot of Power problems . I wanted a simple low cost Short circuit protection circuit after the rectification stage to protect sensitive Mosfets and costly transformer. I have made a 150 Watt Mosfet Stereo Amplifier and I was searching for a good, simple short circuit protection circuit for this amp, I only found protection circuit for speakers in your blog and I have added it. I really found very very useful circuits in your blog and I have tried most of it, Thanks for that.
#PROT ON AMPLIFIER TV#
The next simple short circuit and overload protector design presented here can be used for protecting valuable mains operated gadgets like amplifiers, TV sets, DVD players or any other similar appliance. The capacitor at the base of the transistor keeps the transistor switched for a few seconds so that the relay does not oscillate randomly. Since the relay coils support the amplifier connection with the speaker output, disconnects the amplifier from the output connection, preventing the amplifier devices from a possible damage.
#PROT ON AMPLIFIER DRIVER#
This instantly triggers the opto transistor which in turn switches ON the transistor driver and the associated relay mechanism. The current threshold across the above resistor is sensed by an LED inside an optocoupler, which lights up the moment a short or overload conditions is sensed. Normally a low value resistor is usually employed at the output of mosfet amplifiers, the current developed across this resistor can be well exploited for tripping a relay in case it exceeds the safe maximum current value. The given amplifier short/overload protection circuit diagram, shows an inexpensive design using just a single transistor for implementing the intended feature. The above mishap can be prevented by adding a small circuit for detecting a short circuit conditions at the outputs of an amplifier. Whatever might be the reason, the end results in the destruction of the precious MOSFETs inside the amplifier box. A short circuit at the output may be caused due to mishandling or ignorance from the part of the user. While working with high power amplifier designs, two things become crucial, the protection of the amplifier and the protection of the speakers from an accidental over current influx.Įspecially when the amplifier design involves costly mosfets, the design becomes specifically vulnerable to short circuits at the outputs.
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