What Happens if You Power a DC Device with AC Voltage?

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SUMMARY

Powering a DC device with AC voltage, such as supplying 10 V peak-to-peak AC to a device rated for 5 V DC, can lead to significant damage. Devices lacking reverse-bias protection may experience component failure due to reverse polarity. Integrated circuits and processors require a stable DC supply to function correctly; fluctuating voltage levels can cause them to turn on and off, potentially leading to malfunction. Therefore, it is critical to adhere to the specified voltage requirements and avoid using AC power for DC devices.

PREREQUISITES
  • Understanding of DC and AC voltage characteristics
  • Knowledge of reverse-bias protection in electronic circuits
  • Familiarity with integrated circuits and their power requirements
  • Basic principles of voltage regulation and power supply design
NEXT STEPS
  • Research the effects of reverse polarity on electronic components
  • Learn about voltage regulation techniques for DC devices
  • Explore the design of power supplies for integrated circuits
  • Investigate the specifications and protections in common electronic devices
USEFUL FOR

Electronics engineers, hobbyists working with DC devices, and anyone involved in designing or troubleshooting electronic circuits will benefit from this discussion.

salman213
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I was just curious what would happen if a device working at for example, 5 V DC voltage, is given 10 V peak to peak AC voltage. Would the device still operate?

maybe it depends on the device but can someone briefly explain ..?

thanks!
 
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My opinion is that it would depend on the device. If it didn't have reverse-bias protection, you could potentially fry some internal components. I also think it could be turning on and off at the same period as the input frequency.
 
would the on and off result from not getting enough voltage to run it. For example when it is above a certain voltage it is on, but when it drops it turns off until 1 period passes?
 
It would depend on device but I am sure that if it is specified that it requires DC then it must have DC.
Most devices contain integrated circuits, processors etc. These require a steady DC supply to work correctly with reference to a steady ground point. You would then be supplying 5 volts for one half cycle and then -5V for the other and obviosly crossing the 0V line at the rated mains frequency in your country. Most circuits will have some sort of protection to protect against reverse polarity but the IC's etc will not work for below a certain voltage and also reverse polarity.
So the answer to your question is don't do it!

http://www.powerups.co.uk
 
Most likely this can only be answered by an "old timer". I am making measurements on an uA709 op amp (metal can). I would like to calculate the frequency rolloff curves (I can measure them). I assume the compensation is via the miller effect. To do the calculations I would need to know the gain of the transistors and the effective resistance seen at the compensation terminals, not including the values I put there. Anyone know those values?

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