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WP34s Repurposing Journey PhotoJournal
02-04-2015, 06:41 AM (This post was last modified: 02-04-2015 06:45 AM by MarkHaysHarris777.)
Post: #19
RE: WP34s Repurposing Journey PhotoJournal
Some of you may have noticed that the dandy brilliant LM339N from TI has four open collector comparators and that two of them are hanging around uselessly wondering what their place is in the scheme of things (like many of us). What shall we do with the other two op amps?
Glad you asked.
Using pretty much the same schematic (for the Tx Rx monitors) amp (3) will monitor the reset pin voltage (J32), and amp (4) will monitor the 3.4 Vcc line voltage. If the reset pin (J32) from the 34s goes high (this is a signal that the 34s is powered on) amp (3) will signal this by turning on Q out and lighting our LED (this is going to be our visual indicator, since the screen on the 34s looks 'dead'); when we initiate the reset ground shot, amp (3) Q out will turn off the visual indicator (probably a green LED, haven't decided yet). Amp (4) will monitor the 3.4 Vcc line voltage and turn on a red LED should the voltage drop below 2.8v, or maybe 2.7v, volts. At any rate, this indicator is a visual warning (normally off) that indicates potential problem with the flash, or perhaps even a warning not to proceed with the flash.
Coming soon.

PS I am remaking my Katie clips (sigh). I chose the wrong material. The aluminum is soft enough to work with, hard enough to hold, but apparently too brittle for the long haul; one clip (tip) broke off. Fortunately because of the large pins, the other clip held fine and the transfer completed. But, I now need to repair the Katie clips. I'm going for brass this time (same design) only this time I'm going to reinforce the tips of the clip with a ball of solder on the lower inside. (I'll send pic when done). This should prevent the clips from 'breaking' or bending under pressure of the pogo pins; the real problem, again, is that the pogo pins even with pointed tips need to be held securely (3 mm travel at least) BUT without popping loose, or breaking. Well, I've already been back to the drawing board, now its back to the work bench.


Kind regards,
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RE: WP34s Repurposing Journey PhotoJournal - MarkHaysHarris777 - 02-04-2015 06:41 AM

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