A quick video to show how I made the 12 volt adapter that plugs into my car cigarette lighter to maintain the car's computer memory and clock / stereo settings while the car's battery is disconnected.
Great video. Just used this on my Crown Vic to save the memory - was simple to make - got a 4.1A 12V general AC to DC adapter out of Frys, a cigarette socket, and a diodes to match, and worked great!
Just made one myself. You, are a godsend sir! The one I bought at Frys electronics here in Phoenix was a Philmore 48-130, and I used 2 (two) NTE 5800 diodes in parallel to support the 4.1A it supports. Working great - using it now, as a matter of fact, so I can change my alternator!
Good description, nice video, John. I've seen these made with little 9v batteries, but I've been reluctant to use them because I don't like the idea of downshifting voltage from 12 to 9. The diode is a great idea.
Good description, nice video, John. I've seen these made with little 9v batteries, but I've been reluctant to use them because I don't like the idea of downshifting voltage from 12 to 9. The diode is a great idea. I've sometimes wondered if there may be diodes internally in the car circuit that might interfere with retrograde current flow from the 12 v adapter. Evidently, not in most. Doing it through the adapter keeps the engine compartment uncluttered.
@phonemanlen Yes, this is normal. It measures such high voltage when there's no electrical load on it. On the adapter body it will say like 12V and 0.2 Amps or something (for example). That means it will provide 12V if you're drawing a full 0.2 Amps. As you draw more current (Amps) the voltage will reduce. That's why when you're drawing under 0.2 Amps (or zero amps with no load) the voltage is higher. /John
In the small plug block, AC is stepped down from 120VAC to 12VAC then converted to DC via full wave rectifier using 4 diodes. Why add another diode on the positive?
@markstevenbuisness I did use this thing in my video: VW Golf Cabrio Starter Replacement DIY 1 (Part 1/2). Are you interested in making electronics? Maybe I'll make some future videos on how to make some circuits. Thanks for watching and commenting. /John
Appreciate what you do. Does the cig socket of the vehicle need to be live? And can we just connect a battery tender to the vehicle terminal leads and then disconnect the battery from them?
you dont need this for the car computer. it keeps its info. you will need this on older cars that do not keep the factory presets. most modern cars will save the presets now.
Lalo Herrera You could. If you're removing the battery then you need to connect the clips to the battery cable leads instead, and make sure they are isolated so they don't touch the chassis. I usually put plastic bags around them. The cig. lighter socket is just another option. If I used alligator clips someone would probably suggest the cig. socket. /John
good point. I just use the alligator clips that have the rubber boots around them, much easier to work with. I have done some electronic diagnoses and they work pretty good.
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Great video. Just used this on my Crown Vic to save the memory - was simple to make - got a 4.1A 12V general AC to DC adapter out of Frys, a cigarette socket, and a diodes to match, and worked great!
Just made one myself. You, are a godsend sir! The one I bought at Frys electronics here in Phoenix was a Philmore 48-130, and I used 2 (two) NTE 5800 diodes in parallel to support the 4.1A it supports. Working great - using it now, as a matter of fact, so I can change my alternator!
Good description, nice video, John. I've seen these made with little 9v batteries, but I've been reluctant to use them because I don't like the idea of downshifting voltage from 12 to 9. The diode is a great idea.
cheers was thinking about something like this for my VR6 whilst its laid up over the winter.
Good description, nice video, John. I've seen these made with little 9v batteries, but I've been reluctant to use them because I don't like the idea of downshifting voltage from 12 to 9.
The diode is a great idea. I've sometimes wondered if there may be diodes internally in the car circuit that might interfere with retrograde current flow from the 12 v adapter. Evidently, not in most. Doing it through the adapter keeps the engine compartment uncluttered.
@phonemanlen Yes, this is normal. It measures such high voltage when there's no electrical load on it. On the adapter body it will say like 12V and 0.2 Amps or something (for example). That means it will provide 12V if you're drawing a full 0.2 Amps. As you draw more current (Amps) the voltage will reduce. That's why when you're drawing under 0.2 Amps (or zero amps with no load) the voltage is higher. /John
@krazy45cat No, it's not a Zener diode. Just a regular PN junction type diode. Thanks for watching and commenting /John
In the small plug block, AC is stepped down from 120VAC to 12VAC then converted to DC via full wave rectifier using 4 diodes. Why add another diode on the positive?
@markstevenbuisness I did use this thing in my video: VW Golf Cabrio Starter Replacement DIY 1 (Part 1/2). Are you interested in making electronics? Maybe I'll make some future videos on how to make some circuits. Thanks for watching and commenting. /John
Question: Are 12V switching power adapters and 12V linear power adapters both suitable as car memory savers?
Appreciate what you do. Does the cig socket of the vehicle need to be live? And can we just connect a battery tender to the vehicle terminal leads and then disconnect the battery from them?
@mattd28 Thanks for watching and commenting. /John
@phonemanlen You're welcome. /John
I bought one of the one that uses a 9volt battery . I kills the 9volt battery in a short period of time . Nice tool ! Is taht a zineard diode ?
cool deal, yo should hook it up to the car and show us how it works when attached..
you dont need this for the car computer. it keeps its info. you will need this on older cars that do not keep the factory presets. most modern cars will save the presets now.
why not just use alligator clips at the ends, and then connect it up to the car battery
Lalo Herrera You could. If you're removing the battery then you need to connect the clips to the battery cable leads instead, and make sure they are isolated so they don't touch the chassis. I usually put plastic bags around them. The cig. lighter socket is just another option. If I used alligator clips someone would probably suggest the cig. socket. /John
good point. I just use the alligator clips that have the rubber boots around them, much easier to work with. I have done some electronic diagnoses and they work pretty good.
Hey i think ur explanation is wrong...diode had polarity represent positive nd negative ur explanation is totaly wrong