Price - Stock No
190 - Flying Lead Input
Price - Stock No 191 - 12V Accessory
This kit provides a charging source for USB
- Check the P.C.Board for damage to
tracks. Any breaks can be soldered over. Check with a multimeter
or electronic circuit tester.
- Identify the resistors, see Resistors.
- Solder in place - see Soldering
- Examine the 7805, note the pin names and orientation from
the above diagrams. Bend the legs of the 7805 so that it lies flat on
- Insert the 7805 and solder.
- Insert the USB socket, making sure all pins and mounting
lugs penetrate the PCB.
- Using pliers fold the lugs to secure the socket.
Solder the lugs to the PCB.
- Solder the 4 pins of the USB socket.
- Insert and solder the two PCB pins.
- Identify the capacitors, the 100uF electrolytic is
polarised and must be inserted in the correct orientation. Solder.
- The 0.01uF greencap is not polarised. Insert
- Identify the legs on the LED. Ensure it is inserted
with the correct polarity and solder.
- Strip and tin the ends of the figure 8 wire.
See Tinning Wire
- Connect one end of the wire to the PCB
Operation and Testing
Take Care - the 7805 will dissipate heat. Temperatures in
excess of 70 oC can be expected when charging.
- Apply the correct voltage to the input. The LED
- Check the USB output socket - Using a multimeter, black
lead on GND (Pin 4), measure the voltage on the other pins of the USB
socket. 5V on each pin is correct.
- Attach your USB device, charging will
This circuit uses a 7805 voltage regulator to provide a
constant 5 V source. The 7805 is supported by the two
The regulated 5V is provided to the USB device at pin
4. The data lines pins 2 & 3 are biased high through the 10K
The 220R resistor limits the current through the LED to an
Troubleshooting, if necessary will involve careful
checking of locations and polarity of components, in particular the diodes and
the SCR. Re-solder all joints and check to make sure you
have not bridged across between any two adjacent
component legs. The end of a broken hacksaw
blade sharpened on an emery wheel is a good tool for
cleaning between soldered joints.
Contact CdS electronics