Hi Indeed very cool pictures.
If the lamp is like most gas bulb lights, there is indeed a “strike voltage” required to get things going (or an RF excitation). There inevitably is some temperature dependence as well. A constant current driver might be the better bet. Bob > On Feb 20, 2018, at 4:30 AM, Poul-Henning Kamp <p...@phk.freebsd.dk> wrote: > > -------- > In message <aabpjy7pfajkd...@smtpout01.dca.untd.com>, cdel...@juno.com writes: > >> Here is a PIX of the optical unit from a 5065A totally removed from the >> shield assembly. > > Nice! > >> Left to right: >> >> Lamp assy >> lamp oven cylinder >> lamp reflector/convection block/diffuser >> Rb85 filter cell > > It looks like there is a square filter of some kind > between the reflector and the filter cell ? > > I've been thinking a little bit more about power for the lamp assembly. > > Since I have the lamp on the bench-supply I am going to plot lamp > voltage vs. photo-I because it looks like a threshold rather than > a linear relationship. > > If that is the case, I think it will make sense to give the lamp > its own adjustable voltage regulator (LM317), so the power can be > reduced to what is optimal/necessary without having to take the > lamp apart and change a resistor. > > A 1R resistor between the 22-30V supply and the LM317 will make it > easy to monitor lamp current, and a 300mA short-circuit protection > is a nice bonus. > > If need be, the regulator could start out at 20V and drop to something > lower in a matter of minutes. > > Actually, now that I think about it, I should try to measure if it > is gives better stability if I drive the lamp with constant current, > constant power, constant voltage or constant photo-I... > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > _______________________________________________ > 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. _______________________________________________ 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.