Hi I think you will find that the TBolt pulls about 750 ma at turn on off of the +12V supply.
Bob On Jun 27, 2013, at 8:37 PM, Bob Stewart <[email protected]> wrote: > Thanks for the correction Bob. I don't know what made me think it was an > on/off oven. The OC-050 datasheet gives a drain of 12 watts in warmup and 4 > watts in run mode, so I went with that in the post I just made, calculating > the loads, etc. > > Bob > > > > > ----- Original Message ----- >> From: Bob Camp <[email protected]> >> To: Discussion of precise time and frequency measurement <[email protected]> >> Cc: >> Sent: Thursday, June 27, 2013 7:27 PM >> Subject: Re: [time-nuts] +12 Volts 1A (plus a bit) supply? >> >> Hi >> >> The OCXO in the TBolt has a linear controller. It drops back to about 150 to >> 250 >> ma on the +12 line after warmup. It's been at least 40 years since I saw an >> on/off oven control in production …. >> >> Remember that the +12 feeds the oscillator circuit. The more crud on the 12 >> volts, the worse the phase noise of the output. A linear regulator is a good >> idea. >> >> Bob >> >> On Jun 27, 2013, at 3:49 PM, Bob Stewart <[email protected]> wrote: >> >>> Hi Hal and other responders, >>> >>> I believe that the OCXO uses an ON-OFF type of regulation. So, no, it >> doesn't use 1A all the time. Maybe I should just put an ammeter in the line >> and see what kind of duty cycle it has after it's at temperature. >>> >>> >>> I tried a 7812 regulator with a small dissipator on it. It goes into >> overheat mode almost immediately and the output voltage starts quickly doing >> down. The case does have provisions for a single TO-3 transistor conducting >> heat to the back of the case with no radiating fins. I had briefly >> considered >> using a zener and a 2N3055. >>> >>> I think that instead of worrying this to death, I'm just going to use a >> brick to get it together, and then if something comes up later that I like, >> I'll put that in. I did like the looks of that PT5102 but it's at end >> of life, and 1A is right at it's limit. I've given some consideration >> to seeing whether I can pull a few turns off the transformer secondary, as >> well. >>> >>> >>> Bob - AE6RV >>> >>> >>> >>> ----- Original Message ----- >>>> From: Hal Murray <[email protected]> >>>> To: Bob Stewart <[email protected]>; Discussion of precise time and >> frequency measurement <[email protected]> >>>> Cc: [email protected] >>>> Sent: Thursday, June 27, 2013 2:24 PM >>>> Subject: Re: [time-nuts] +12 Volts 1A (plus a bit) supply? >>>> >>>> >>>> [email protected] said: >>>>> The transformer gives me about 20 volts DC out. Dropping 8 volts >> at 1 amp >>>>> is just a lot of power to void with a resistor. I'd like to >> avoid >>>> having >>>>> that much waste heat in the unit. >>>> >>>> Does it really take 1A after it's warmed up? >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
