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.
