Well the Santapod weekend is coming this weekend. I have one of those phones that have a flat battery after a day. I will be going up to Santapod in the Fiesta as its cheaper on fuel than the Trans-Am, although the Trans-Am is much more fun i need to save the pennies. I do have an inverter that runs from a cigarette lighter, however the fiesta is so basic it doesn't have one of those.
I found the Duracell made a USB charger, its basically a battery pack, you plug you phone into it for it to charge. Duracell 5 hour battery charger. However at 1800mAh, and the phone battery is 1600mAh, its only going to around double the length of the phone battery. I need something bigger, as going up Friday, coming back Monday, and there are 2 phones to charge. So I have a brain wave. Why not make my own.....
Looked on my desk, just happen to have a USB-A receptacle. Need to convert 12V downto 5V, a 7805 regulator is just the ticket for that, add some capacitors, and a heat sink just to keep the 7805 nice and cool, its a 2A device, and charging take around 400mA, so the heat sink is a bit of an overkill.
View attachment 23023
All assembled and tested, now to add some resin to help make it a little more robust
View attachment 23024View attachment 23025
View attachment 23026
The quick schematic, in case you wonder what parts I used. The capacitors don't have to be that size. I went for them as they were in the drawer, and basically to need different values on the input to the 7805 as you do to the output. I'm charging from a spare 12V car battery, do the voltage from that will be dead smooth. The 7805 oscillates a little so its for smoothing the output.
Roll on the weekend.
I found the Duracell made a USB charger, its basically a battery pack, you plug you phone into it for it to charge. Duracell 5 hour battery charger. However at 1800mAh, and the phone battery is 1600mAh, its only going to around double the length of the phone battery. I need something bigger, as going up Friday, coming back Monday, and there are 2 phones to charge. So I have a brain wave. Why not make my own.....
Looked on my desk, just happen to have a USB-A receptacle. Need to convert 12V downto 5V, a 7805 regulator is just the ticket for that, add some capacitors, and a heat sink just to keep the 7805 nice and cool, its a 2A device, and charging take around 400mA, so the heat sink is a bit of an overkill.
View attachment 23023
All assembled and tested, now to add some resin to help make it a little more robust
View attachment 23024View attachment 23025
View attachment 23026
The quick schematic, in case you wonder what parts I used. The capacitors don't have to be that size. I went for them as they were in the drawer, and basically to need different values on the input to the 7805 as you do to the output. I'm charging from a spare 12V car battery, do the voltage from that will be dead smooth. The 7805 oscillates a little so its for smoothing the output.
Roll on the weekend.
