Timeline for How to drop the voltage of a power supply?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Aug 12, 2020 at 19:05 | comment | added | D.A.S. | car battery 1R? (not) if CCA = 500A at 7.5V then ESR=<0.01R = (12.5-7.5)/500, the FOXsur is a cheap solution to desulphation if done shortly after detected or as preventive in parallel with alternator. 5A is a narrow pulse at a rate which can breakdown lead sulphate crystals that raise ESR.. | |
| Aug 12, 2020 at 14:04 | comment | added | Sneaky Puffin | Good point Andy, that was a bit to generalised. Obviously, I was describing the scenario before the described setup is connected to a battery. 21V through the 3.9R resistor not connected would measure as 21V. The moment you connect the other end of the 3.9R Resistor you are introducing a new resistance to the circuit (Quick google suggests that car batteries are around 1R) so now you would have R1 3.9R & R2 1R giving you in theory 4.285V over R2. Regardless of my abbreviated description this is not the solution. | |
| Aug 12, 2020 at 14:02 | comment | added | D.A.S. | Well maybe slightly FOXSUR 12V 5A Pulse Repair Charger | |
| Aug 12, 2020 at 13:58 | comment | added | Andy aka | This would not change the voltage in the slightest - don't be too general about this. I know what you mean but you need to spell it out when connected to the battery. | |
| Aug 12, 2020 at 13:00 | history | answered | Sneaky Puffin | CC BY-SA 4.0 |