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The laptop has USB 2.0. The TomTom has a Micro USB / USB cable. Connected to the lighter the TomTom shows that it is running from battery power, connected to the laptop it shows charging from external power adapter. The lighter will power other devices.
As the USB and the lighter (with adapter plugged in) both supply 5v how is it that it works only from the computer when directions are not required.
rambie
Posted 2015-01-16T00:32:27.870
Reputation: 11
2
The 'furnace' line is current-only limited by some basic electronics and a fuse. Its voltage fluctuates freely. The 'electronics' line is both voltage regulated AND current-limited, and the fuse is only for safety. Your TomTom's 12VDC to 5VDC converter might be cutting out due to voltage fluctuations - which is good regarding the alternatives - boom, fire, and utter destruction. Connect it to the vehicle's 12VDC utility line (instead of the cigar-lighter plug) and the converter should work fine.
arch-abit
Posted 2015-01-16T00:32:27.870
Reputation: 455
This is a good answer, but are you sure this would be the issue? Many device makers purposefully cripple devices based on amperage range. More details here: https://learn.adafruit.com/minty-boost/icharging
– JakeGould – 2015-01-16T04:25:36.577I guess Apple might have some technology preventing voltage as related to current work as we engineers predict they should. Since voltage is set at 5VDC, current has nothing else to do than fluctuate, so I guess some VCR (voltage-controlled-resistor) might do the trick to sink some current - Apple has it, generic USB chargers do not. I have no idea what you have for OUTPUT, but for input from a car try to verify the plug you use. – arch-abit – 2015-01-16T04:44:45.037
Some power adapters are not enough current (miliiamps) for some devices, plus some methods of charge recognition exists for higher current charging. Some are just made cheeply and work somewhat on many devices, but not on all devices. I went through 3-4 cheap cigar lighter adapters before I got higher priced higher powered better quality ones that work with everything. Also the quality of the wiring from the adapter can change how much drop there is through the wiring itself. Either find OEM devices that are designed to work with the device, hack the electronics, or just find better parts. – Psycogeek – 2015-01-16T02:05:01.970
Please clarify... Vehicle 'lighter' plug, the one that heats a coil inside the plug hot enough to start a cigar? Are you using the 12VDC 'utility' line dedicated to power electronics or the 'lighter' line dedicated to create a furnace? – arch-abit – 2015-01-16T03:21:25.113
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Companies much around with amperage on chargers. So while it is technically 5 volts and can potentially charge the device, TomTom could have circuitry in place that will only—and I mean only—charge the device in the right range of amperage. Apple is notorious for doing this with their iPods & iPhones. This article on the MintyBoost and the challenges the creator of the charger had getting it to work with Apple devices goes into excruciating detail on the efforts Apple makes to prevent 3rd party chargers from working with their devices.
– JakeGould – 2015-01-16T04:24:03.630