[time-nuts] Thunderbolt Power Supply Question

Ed Palmer ed_palmer at sasktel.net
Mon Apr 26 16:56:46 EDT 2010


Arthur Dent wrote:
> The +12VDC supply (internal to the sealed oscillator) supplies both the oven and the oscillator circuits. I think you'll find that internally this +12VDC goes to the heater circuit as well as through a regulator to the oscillator which is running on something like +7VDC. This is speculation at this point but a number of similar type oscillators I've checked are set up this way and even have a temperature compensated regulated reference voltage out of about +7VDC to feed a pot or EFC circuit. For instance the HP 10811 has an internal +5.7VDC regulated supply for the oscillator circuit
>
> One crude way to check is to take a removed 10Mhz oscillator Trimble oscillator and power it from a bench supply at +12 and let it stabilize. Then reduce the supply voltage slowly and see where the output level and/or frequency start to change. If you see no change until you've reduced the voltage a few volts then the oscillator has an
>  internal regulator for the oscillator circuit.
>   
Every oscillator has a spec for frequency shift due to power supply 
variation, but maybe you'd see a big change when you lost regulation.  
Have to think about that.

Ed





More information about the time-nuts mailing list