Fantastic! Having the possibility of getting a set of voltages would be very nice, that way all voltages needed for driving a Dekatron/Polyatron like guide bias voltage, guide stepping voltage, reset/set pulse voltage could be had from one small transformer (and possibly the voltage for driving a Nixie too - Anode and bias voltages). For ordinary Dekatrons all of these voltages have the same ground reference and can usally be solved by simple resistive voltage dividers, but with some types, like the Polyatrons, the circuit is simplified by having separate grounds. I think the market for such a power supply is not that big but it might mean that more people use Dekatrons to build clocks (which of course will drive the price up on the usable Dekatrons like the Russian A-101 to 103 and the European/american GS10C/6476 and similar selector types). Maybe off-topic, but I am thinking of what I would like to build - a nice small bench PSU. For anyone who wants to build one or more small bench power supplies for experiments with Dekatrons with good regulation it is always welcome to have separate voltages available on the "primary" side of the pass element so you don't need to cool off too much heat in the pass element. Having the possibility to change range for the input voltage to the pass element reduces the size of the heatsink you need. Making a 0-600V powersupply and using only 5V output voltage means that you drop 595V across the pass element at whatever current you draw and that amounts to a lot of heat, but with a switchable range of "primary" voltages you will have to cool off less heat. /Martin
On Tuesday, 13 August 2013 01:39:16 UTC+2, taylorjpt wrote: > >Regarding isolation, some circuits are easier to build if the different > high voltages needed are isolated from the low voltages (digital and/or > analogue) and in the case with Russian Dekatrons like A-201 (Polyatron) it > is a lot easier to design a circuit with isolated power supplies than those > that use a common ground. > > Got it... It should be possible to get any isolated voltage or set of > voltages by using a secondary that is ratio metrically related to a sensed > output winding. For a variable input voltage a grounded secondary (vs a > tapped winding) is needed or else the output will vary as the input changes > unless you subtract the input voltage from the feedback equation. For > instance, to get 600V on an isolated winding you can develop 200V across a > 60 turn secondary that is fed back to the controller and then use a > floating 180 turn secondary to generate the 600V output. As long as there > is minimal loading on both windings, line and load regulation is actually > pretty good. This is used in a lot of newer AC adapters to get rid of the > optocoupler by simply measuring the voltage on the primary during flyback > to get a sense of the secondary voltage. I'll give that a try when my > boards come in next week. > > jt > > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/8fbf47cf-ee47-4bf9-a2a9-ea6a9748ae84%40googlegroups.com?hl=en-GB. For more options, visit https://groups.google.com/groups/opt_out.
