[time-nuts] Temex LPFRS-01

MailLists lists at medesign.ro
Sat Mar 17 09:59:30 UTC 2012


Hello all,

a friend purchased from the bay a <subj.> in the LPRO configuration. 
After some problems encountered during the first power ups, he asked for 
help - I'm passing the questions further...
After about 9 minutes of warm-up from room temperature (22°C) the lock 
signal goes low, but after a short time starts to switch low/high with 
decreasing low periods, until it remains high with short low pulses, 
spaced at about 2 seconds. After power-down, and sufficient cooling 
time, the cycle repeats.
First step was to reapply the thermal interface to the integrated Al 
radiator, which helped a bit, the time during which the unit is locked 
growing slightly.
Next step was forced cooling, which helped more, so the lock loss could 
be attributed with high probability to elevated operating temperatures. 
The temperature of the base plate (integrated Al radiator) at which lock 
gets lost is about 40°C, so for a reasonable operation it should not 
pass about 36°C, at which the power consumption raises to about 17W. 
That also means that for a 1°C/W heat sinking - obtainable with a larger 
passive HS or active cooling - operation above 30°C ambient gets 
practically impossible (except refrigeration, Peltier, etc.).

Any further help or suggestions are welcome.

Regards,
bbg



More information about the time-nuts mailing list