On Fri, Jul 26, 2013 at 11:17 AM, steve gunsel <steve@sgteq.com> wrote: > Hi, > > I recently purchased a surplus Trimble Thunderbolt and would like to get > it going. The 24 volt units have a fairly wide range of acceptable > voltages. The only power supply specs I can find for mine specify +5, -12 > and +12. No min-max is specified. I have a power supply that has +5, +15 > and -15 volts available that I'd like to use but not unless within > acceptable limits. Does anyone know what the power supply specs are? It is very easy to take 15V to 12V with a three terminal regulator. Use a good heatsink on the +12V reg. You can drop some of the voltage ahead of the regular with power resister. That said, this thing is going to run 24x7 for hopefully years and you don't want to pay for all that wasted power. Get a 12V power supply On the other hand you can put that heat to good use. I designed a fan controller with a smal temperature sensor, an opamp and a power transistor. It keeps the temperature inside the box reasonably constant. I have the power supply (salvaged from a Cisco router) the regulator board and the Thunderbolt all in an old Disk Array enclosure. So there are several correct answer, depends on how much work you want to do. Simplest is to replace the power supply. Chris Albertson Redondo Beach, California

Hi Ideally you would like a linear supply (not a switcher) on the +12 and +5. That's not always very easy. If you are not worried about phase noise, the need for linear regulation is reduced. Depending on the switcher, there may be some impact on ADEV, but that's not real common. Bob On Jul 26, 2013, at 3:47 PM, Chris Albertson <albertson.chris@gmail.com> wrote: > On Fri, Jul 26, 2013 at 11:17 AM, steve gunsel <steve@sgteq.com> wrote: > >> Hi, >> >> I recently purchased a surplus Trimble Thunderbolt and would like to get >> it going. The 24 volt units have a fairly wide range of acceptable >> voltages. The only power supply specs I can find for mine specify +5, -12 >> and +12. No min-max is specified. I have a power supply that has +5, +15 >> and -15 volts available that I'd like to use but not unless within >> acceptable limits. Does anyone know what the power supply specs are? > > > It is very easy to take 15V to 12V with a three terminal regulator. Use a > good heatsink on the +12V reg. You can drop some of the voltage ahead of > the regular with power resister. > > That said, this thing is going to run 24x7 for hopefully years and you > don't want to pay for all that wasted power. Get a 12V power supply > > On the other hand you can put that heat to good use. I designed a fan > controller with a smal temperature sensor, an opamp and a power transistor. > It keeps the temperature inside the box reasonably constant. I have the > power supply (salvaged from a Cisco router) the regulator board and the > Thunderbolt all in an old Disk Array enclosure. > > So there are several correct answer, depends on how much work you want to > do. Simplest is to replace the power supply. > > Chris Albertson > Redondo Beach, California > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.