1077049 - [Flame] with the power tool attached, camera flash does not fire properly

Status: RESOLVED WONTFIX

(Powertool Graveyard :: Hardware, defect)

Description

[No-Jun Park [:njpark]]

STR: connect the powertool setup to Flame device, and start the test in the GUI
Open a camera app, and with the flash set to always on, take a photo

Expected:
Flash fires normally
Actual:
Preflash fires, but the main flash does not fire during the shot taking.  On the graph, there is a sharp drop in current to -250mA for a moment, then it shoots back up.

Change to camcorder mode, enable flash, and take video
Expected:
Flash is continuously on
Actual:
Flash is on momentarily, then gets turned off right away

Comment 1

[No-Jun Park [:njpark]]

Attachment: Camcorder_Flash_On.csv

Comment 2

[No-Jun Park [:njpark]]

Attachment: Photo_Flash_On.csv

Comment 3

[Jon Hylands [:jhylands]]

I've validated that this happens on my harness as well.

Comment 4

[Jon Hylands [:jhylands]]

So this appears to be an issue with the digital switch chip I am using to allow the battery to be disconnected. It is rated for 2 amps, with an absolute maximum of 2.4 amps, and since the voltage on the battery is dropping 300 mV, that implies the flash is trying to pull 3 amps from the battery.

I'm going to build a new ammeter board, and replace that chip with a soldered on bypass jumper. I'm betting this won't happen after that.

Comment 5

[Jon Hylands [:jhylands]]

So, after doing some investigation, I've got some answers.

According to an engineering contact at T2M, the flash is supposed to take a max of 1.6 amps.

I built an ammeter board without the switch chip, and soldered on a jumper that connected the leads. In video preview mode, with the flash off, it consumes about 600 mA. In video preview mode, with the flash on, it consumes between 2.0 and 2.2 amps.

This is still outside the boundaries of what the switch chip on the ammeter can handle, so the camera can't pull enough current, and the flash doesn't come on.

Right now, I'm not planning on fixing this. No-Jun, if you really need to measure current with the flash on, let me know and I'll send you a special ammeter that doesn't have the switch.