Introduction: $1 USB Car Charger From 3 Parts
You would like to travel on car, but you haven't charger for your phone/navigator/camera? With my instructable you can make it very easy. You need only 3 parts, that you can buy for $1!
Step 1: Parts
Step 2: Whats Need
1. Soldering-iron.
2. Some wires.
3. Glue gun or another glue.
Step 3: Voltage Regulator
At first you need to solder wires to voltage regulator and isolate it.
Step 4: Connect Voltage Regulator
Connect Input wire via capacitor (0.33) to gnd. After connect Output wire via capacitor (0.1) to gnd. Connect Input to "+" of box and connect gnd to "-" of box.
Step 5: Connect USB
Now you need to connect USB port. Connect GND to GND and 5V to Output pin on Voltage Regulator.
Step 6: Test It
To test you can use multimeter or any usb tester.
Step 7: Plase All in Box
You need to cut a hole in the top of box and plase all to box. After you need to glue USB port
Step 8: P.S.
Thank you for reading my instructable. I try to make instructable very short becouse i don't know english well. If I made a few mistakes, please forgive me)
5 Comments
7 years ago
That setup will get over 125C if you draw about 200mA. 7805 has a theta of around 65C rise per watt dissipated. You will have 7-9V drop (14V to 5V). The voltage drop times the current is the power dissipated in the regulator. That power times the theta value is the temperature rise of the part. The plastic used in that adapter is probably only hard to about 100C. At 200mA this will melt the plastic and probably short the whole circuit out in the lighter socket. Please be careful with this and monitor it closely.
Reply 7 years ago
If you will use good radiator it be around 50C°-70C°.
Reply 7 years ago
Depending on your part supplier, the LM7805 can have a Theta of 19 or 65 C/W. That is a huge difference. So I reran the calculations. At 200mA with Theta = 19 C/W you will hit about 60C max. I also ran the calculations at 500mA and put them in an attached image to show others how to do them. It looks like if you have a TI part you will probably be OK but still running really hot. I'm still concerned that since there is no air flow over the package it will heat up past the melting point of the plastic.
Keep plugging away!
7 years ago
Looks good, thanks for sharing! :)
Reply 7 years ago
Thank)