What voltage range is acceptable for 12V electronics?

Other Hardware General Electronics
1

Hi all,
Firstly, I apologize if this is the wrong category, I just thought it seemed like a good bet, as the topic does not involve an Arduino. I've got a sick nixie clock that I got on ebay and its power source is a transformer providing 12VDC. I'd like to install it in a vehicle which, of course, is a 12V system. My question is: even though automobiles have a 12V system it is not always 12V exactly; while running they can be a bit over 14V and while cranking or if the lights were left on overnight or something it can be like 9V, will the electronics in the clock be cool with that, or will it mess things up? Thanks!

2

There is no simple answer to your question. It depends entirely on the design of the clock.

And you should allow for the automobile voltage going up to 15v while charging.

...R

3

I think I'll pickup a 12V step down step up regulator

4

The battery voltage and actual voltage used by something like a clock is different. They use voltage regulators to drop voltage to something needed such a 5v or 3.3. Designing digital circuits for auto can be challenging due to the noise. An LM7805 can easily handled the voltage range seen at a car battery.

5

If your battery is down to 9 V you most certainly will not be able to start the car! :roll_eyes:

6

wolframore:
The battery voltage and actual voltage used by something like a clock is different. They use voltage regulators to drop voltage to something needed such a 5v or 3.3. Designing digital circuits for auto can be challenging due to the noise. An LM7805 can easily handled the voltage range seen at a car battery.

Maybe - but we don't know it for the specific clock the OP is trying to use. Hence #1 remains the correct answer. It depends on the design of the clock.

OP mentions the clock uses a 12V transformer; it doesn't make much sense to use a 12V transformer and a 7805, when you could also use a 5V transformer to get to that 5V directly. Saves components, cheaper to build, less heat to deal with.

Even more so, those tubes normally require 12V.

Without access to the schematics of the electronics in that clock, it's all guesswork. It may work fine. It may set the clock on fire. There's just no way to tell based on the information available.

7

Hello,

You can search for a voltage regulator of the SEPIC type, it must raise or lower the voltage as needed.

8

And just to note, in a computer power supply (desktop), to 12V are tolerable 10%, and to 5V are tolerable 5%.

9

wvmarle:
Even more so, those tubes normally require 12V.

Nixie tubes on 12V? No. They require from anywhere to 160 to 180V to light up properly.

// Per.

10

Hi,

I can't tell you what your circuit will accept but I can tell you what the vehicle is specified for:

  1. 6 - 16 Vdc (the 6V is cold cranking voltage, only when the engine is turning over. This is not the typical cranking voltage)

  2. 50 to 80 Volt short term. About 100 ms to 120 ms

  3. 1500 V for < 10 µsec.

11

Zapro:
Nixie tubes on 12V? No. They require from anywhere to 160 to 180V to light up properly.

// Per.

The OP has probably not heard of electroluminicent displays.

Paul