Difference between revisions of "Upd pcb"
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=Wifi radio= | =Wifi radio= | ||
+ | |||
+ | =VCLAMP8= | ||
+ | * The P-FET is static sensitive. | ||
+ | |||
+ | ==testing== | ||
+ | * use the smaller MPJA supplies for the test | ||
+ | * limit the power supply current to ~100mA | ||
+ | * apply 27V - you should see no load current | ||
+ | * (for 1sec) apply 28V - you should see supply voltage drop to ~27.5 - and see 100mA of load current | ||
+ | * the clamp P-FET is not well heat sunk and applying a load current will overheat it. | ||
+ | |||
+ | ==common failures== | ||
+ | * the power resistor fails - typcial it fails "open". With an ohm meter it should measure ~1 ohm. | ||
+ | * the power transistor fails - typically the drain to source is shorted (it should be an open circuit when tested with an ohm meter). Also the gate fails. It should also be an open circuit to the other pins. When failed it has measured between 100 and 200 ohms. |
Revision as of 03:45, 4 January 2009
PFMENU DOCS Aiw_hardware iochan AIW_assembly
Contents
State / Motor Controller
Power Board
IMU
Blue radio
Wifi radio
VCLAMP8
- The P-FET is static sensitive.
testing
- use the smaller MPJA supplies for the test
- limit the power supply current to ~100mA
- apply 27V - you should see no load current
- (for 1sec) apply 28V - you should see supply voltage drop to ~27.5 - and see 100mA of load current
- the clamp P-FET is not well heat sunk and applying a load current will overheat it.
common failures
- the power resistor fails - typcial it fails "open". With an ohm meter it should measure ~1 ohm.
- the power transistor fails - typically the drain to source is shorted (it should be an open circuit when tested with an ohm meter). Also the gate fails. It should also be an open circuit to the other pins. When failed it has measured between 100 and 200 ohms.