17
User ManUal
v1.6
Start by soldering a (preferably black, to indicate ground) wire to the (-) pin of D3. This
will act as your ground for all subsequent tests. Solder a wire of a different color to the
(+) pin of D3. These wires act as your power inputs for testing. Set your power supply to
~18V and connect the supply to the wires you just soldered in.
As before, remove the fuse and cover the left fuse clip in electrical tape. Plug in the
board. Set the interrupter for Fixed mode, max frequency, and max power, and connect it
to the coil.
Test for startup pulses
The signal pathway is:
and
Center pin of IC1
pins 1 and 6 of IC5
The outputs of the gate drive IC (pins 5 and 7) are the AND’ed results of pin 1 and pins
2 and 4, respectively—this should be a 15V signal as shown in the images below. If it is,
you can proceed to the next step. Otherwise check the following:
n
If there is nothing on pin 6 of IC5, check your soldering for shorts and/or replace
the fiber receiver.
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Check the signals on the gate driver. Pin 6 should be 15V, and the inputs and
outputs should match the figures below. If there is input and voltage but no
board to AC power, so you want to cover it with tape to prevent yourself from
accidentally touching it.
You will need to have your board plugged in. Use extreme caution when working on an
energized board! Wear safety glasses.
Using a multimeter, you will measure the logic rails to confirm that they are working. For
the next few tests, ground the black probe of your multimeter to the (-) pin of the low
voltage rectifier (D3) and use the red probe to measure the pins in question.
n
Rectified input, ~22V: (+) pin of D3
n
5V rail: Pin 14 of the 74HCT14
n
15V rail: Pin 8 of UCC27425
If there is no AC input, D3 is suspect and may need replacement. If AC input is low, there
is probably something wrong downstream—chances are one or both of the logic rails will
also be low or absent.
If either logic rail is incorrect, remove the ICs and check again. If this results in all
rails working, you either have a dead IC, or a damaged regulator that is incapable of
supplying current. You should replace the IC of which removal caused the rails to r
eappear, or, if you want to be safe, all the ICs.
If removing the ICs doesn’t restore the rails, check for solder bridges on the board. If
there are no solder bridges, try replacing the corresponding voltage regulator.
If the rails are all present but the coil doesn’t buzz (and your soldering checks out), you
probably have a damaged IC. If you have an oscilloscope, you can use the next section
to determine which ICs need to be replaced. Otherwise, we recommend replacing both
ICs for simplicity’s sake. There is also a chance that the optical receiver is damaged.
C. Debugging with an oscilloscope, function generator, and power supply
Download the Schematics
Schematics and pictures of the board are available
at
onetesla.com/downloads
Antenna
pin 13 of IC2
pin 12 of IC2
pin 11 of IC2
pin 10 of IC2
pins 2 and 4 of IC5
ADULT
SUPERVISION
REQUIRED
