Additional rectification necessary for Tom Tom unit?

[Zubedar]

Hi everyone

I have a doubt I would like to resolve by double-checking with you guys here.

I want to fit a car GPS/Tom Tom unit to a motorbike. There are motorcycle GPS units on the market, but I have this old but nice car one sitting around in a drawer, so I may as well try to use it.

The relevant details are: the unit is designed to run from a car 12V port/cigarette lighter. My doubt is: it's an old-school 1990s motorbike, and my plan is to power the unit by splicing into the 12V system that turns on when the ignition key is turned, so I don't know if additional rectification may be necessary.

The voltage when the bike is switched on but not running is around 12-14V, but it's constant. When the bike is running and the alternator and charging system are engaged, the voltage swings all the time between about 13 to nearly 15V. This follows the bike's reg/rec, which is a basic thing designed to just convert to DC power and limit the voltage for the purpose of charging the battery and powering the lights without damage. But is it fine for a car GPS? I'm not sure how steady the 12V supply is from a car cigarette lighter.

Thanks in advance

 

[Bluejets]

Variation in supply should already be taken care of when you say it is designed for motor vehicle.
Don't know why you imagine extra "diodes" would be required.

Only thing I can imagine may cause a problem is noise from the ignition but with this you will have to " suck it and see".
Motor vehicles are more shielded from ignition and alternator rf noise due to their natural metal encasent, guards, bonnet, firewall etc. etc. whereas motorcycles are wide open.

 

[Zubedar]

Thanks. Yes, I'll probably just splice it in and hope for the best. Just wanted to be careful as I have hundreds of diodes and could whip up a rectification stage or two if smoothing is the cautious thing to do.

 

[(*steve*)]

Rectification and filtering are two different things. And regulation is a third.

 

[Zubedar]

Rectification is the 4 diodes and filtering is the capacitor network, I guess. It's fine with me. I used to occasionally do electronics as a hobby but it's not my field. Thanks