fortunately, everything in the "lab"(basement) is on UPSs so in theory the input voltages to the equipment should be pretty constant and I was already planning on using a linear supply.
as far as magnetic disturbances go, what is a reasonable precaution short of making a muMetal box? On Fri, Oct 7, 2011 at 11:04 AM, Magnus Danielson <mag...@rubidium.dyndns.org> wrote: > On 07/10/11 19:01, Chuck Harris wrote: >> >> There are lots of ways you can unintentionally affect a device >> like an LPRO. For instance, suppose the internal power supply >> dissipates a different amount of heat depending on the input >> supply voltage. This could cause the oven to momentarily shift >> its internal temperature a small amount... which may show up >> as a frequency shift. Or suppose the current change due to >> changing input voltage causes a magnetic disturbance that shifts >> frequency? >> >> We're time-nuts. We are trying to get more from these devices >> than the manufacturer ever intended. > > So you let in normal mains into you lab? >:-) > > If you have linear supplies, you want to > > 1) Steer voltage to be within a tight spec. This will remove variation in > burned power in the linear supplies. > > 2) Run at higher frequency, say 400 Hz, to create smaller ripple after caps, > > 3) With 400 Hz the lower ripple will increase the effective voltage after > rectification and caps, so the "mains" voltage can now be reduced resulting > in even less power dissapation from the power-supply. > > No, I haven't done this, but I realized this after fiddling around with > supplies and verified the ideas with a friend of mine designing supplies all > the time. He also pointed out that many switch supplies tend to run better > when the supply voltage is on the low side of things. > > So, there is things to do if you really want to control your environment. > > Now, how many labs log their mains voltage and correlate frequency > deviations to that? > > Cheers, > Magnus > > _______________________________________________ > 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. > -- --Eric _________________________________________ Eric Garner _______________________________________________ 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.