maximum DC Voltage

[RGG]

What is the maximum DC Voltage that can be applied to a 12DC cicuit board?
Thank you!

 

[Harald Kapp]

12 V - obviously

 

[RGG]

12 V - obviously

Thanks for your reply, but when meetered, my DC power supply indicates 13.97 vdc. Would that make a difference? Would that be too much voltage for a 12vdc circuitboard?
Please excuse my limited electronics knowledge.

 

[Harald Kapp]

1. Have you measured the voltage with or without load? A not so well designed power supply may deliver > 12 V when operated without load, but should regulate down to 12 V when a load is applied.
2. Your question can't be answered more generally than in my post #2. It very much depends on the circuit. Some nominally 12 V circuits may tolerate considerably more than 12 V, others may be picky and insist on a very narrow range, e.g. 12 V +- 5%, 12 V +-10% or so.
   Some may work at higher voltages, but tend to overheat and fail with time, others may fail immediately.
3. When the power supply was supplied with a device, this device should operate with that power supply, but other devices may not.

 

[AnalogKid]

What is the maximum DC Voltage that can be applied to a 12DC cicuit board?

It depends entirely on the circuits on the board. Sometimes a board has an on-board voltage regulator, and can operate over a wide input voltage range. Sometimes there is a delicate component that requires an operating voltage within +/-5%. Without more information, or photos, or product websites, or *something*, we can't say.

ak

 

[crutschow]

my DC power supply indicates 13.97 vdc

What supply are you using?

 

[Harald Kapp]

What supply are you using?

Sounds like a well charged 12 V battey. Matches his other thread.

 

[crutschow]

If necessary, an LDO 12V regulator could be added so the voltage never goes above 12V.

 

[Bluejets]

Ok for say 14v or more but when it drops to nominal, what then? Regulators normally work with a couple of v headroom.

Op is overthinking the whole thing.

 

[crutschow]

Ok for say 14v or more but when it drops to nominal, what then? Regulators normally work with a couple of v headroom.

Yes, standard regulators do, but perhaps you are not familiar with the LDO type I suggested.
Some of those can work down to much less than a volt.
I have a discrete design that works down to the on-resistance drop of a MOSFET.
So the "what then" is, as the input drops below the regulated voltage, the output voltage basically closely follows the input.

Example of one IC linear regulator that has about a 200mV drop (ones with a lower drop are available) below: