I was measuring from the ground off the fuse to the anode pin with no tube connected. I did try the tube and I had nothing going on with the tube. Thinking it was DOA. Not sure thought I may have done something incorrect. I measured with the 180K resistor and a 270K resistor.
John On Oct 11, 1:46 pm, Dekatron42 <[email protected]> wrote: > In most circuits with the EZ10A, and also the EZ10B, the current > through the tube should not exceed 1.3mA when the tube is used > together with cathode resistors of 6.8KOhm resistance (or 10KOhm if > they are capacitively decoupled with 560pF for higher counting > speeds). > > With a supply voltage of 470V this results in an anode resistor of > 150KOhm and with an anode voltage of 560V the anode resistor should be > 220KOhm for the EZ10A. > > The EZ10B can usually be used with the same anode and cathode > resistors but you might benefit from dividing the anode resistor into > two parts, one potentiometer in series with a resistor (the resistor > and potentiometer should have roughly the same value) the resistor > should be decoupled to ground by 22nF for counting stability. > > These values results in a voltage drop of roughly 265 Volts in the > tube and it will result in a voltage drop across the 6.8KOhm resistor > of roughly 9 Volts, which is in accordance to the design parameters > for these tubes. > > To drive the tube at low counting speeds you need a negative guide > pulse of roughly 50V and at high speed counting you need roughly 150V > negative guide pulses. > > If you use the tube outside of these parameters, especially at higher > current it will degrade quite fast according to the articles I have > read, which is the main reason for some tubes not to work that are > sold on eBay. > > On 11 Okt, 20:58, threeneurons <[email protected]> wrote: > > > > Not sure what is going on but I checked the circuit and I am getting > > > 613VDC with the 180K Resistor (R3) in the schematic. I increased the > > > resistance to 270K and I still get 613VDC. Not sure why this is. > > > Anyone have a thought on why I'm getting 613VDC? > > > > John > > > On what side, do you get the 613V. If its the side away from the > > anode, then it may be okay. And it won't change with resistor. What's > > the voltage across the dekatron (anode pin to cathode pin - any > > cathode) ? What's the voltage across the anode resistor ? Divide that > > number by your resistor value (used) to get the current. > > > Dieter got a little carried away with the multiplier ladder. If you > > use capacitors that are too small, the ripple will be outrageous, so > > the average voltage won't go up to the calculated value. In the '120 > > World' you really don't need more than 1.5x multiplication. REMEMBER > > 120V is the RMS (Root Mean Squared - or DC equivalent work) value. The > > sine wave really has a 165V peak value, and ~330Vpp (peak-to-peak) > > value. Look at the following drawing: > > >http://snipurl.com/1asxejhttp://cid-f9db37b8211ce831.office.live.com/...... > > > Refer to image 'D'. > > > If you put 120V (110V, 115V, 117VAC) RMS into that circuit, you'll get > > ~500VDC out, unloaded. The light load most dekatrons put on this > > circuit (assuming an appropriate anode resistor), should not induce > > too much ripple, so the voltage measured won't sage too much. On > > circuit 'D', the lowest located rectifier, and capacitor form a simple > > half wave rectifier & filter, which will output +165VDC, unloaded. The > > left most capacitor's bottom end is riding on the input AC signal. > > It's top end is tied to the anode of the rectifier, that's tapped off > > the +165V. Since this voltage is dynamic (moving), the top end will > > also try to stay in step with the bottom end (this is what the > > coupling caps in your stereo does). But its attached to the +165V > > (thru a rectifier). The bottom of the cap will make a 330V swing from > > -165V to +165V. When the swing is all the way down at -165V, the top > > is forced to +165V by current flowing thru the rectifier. This will > > charge that cap to 330V from top to bottom. As the sine wave goes back > > up, the top will still stay in step, which will make go over the 165V, > > so that diagonal rectifer (now being reversed biased) is switched OFF. > > When the input sinewave hits +165V, the top of the cap will be at > > nearly 500V (495 or there abouts). In the meantime, it would be > > charging the upper right cap. With no load, this circuit will present > > a DC voltage of close to 500V. > > > In the 220V (220, 230, 240) world, you can get away with circuit 'C', > > which will give you 660VDC unloaded. Don't worry too much about the > > voltage. > > > Dekatrons, like nixies (and LEDs) are current devices. Its the current > > flowing thru them that's important. And that's controlled by the anode > > resistor. You can use a 'test' resistor for temporary measurements. > > You need to measure (1) the actual supply voltage, and (2) the 'tube > > drop' voltage from anode to a cathode. Once you have those two, then > > you can determine the 'final' anode resistor value you want, from the > > specs given for that tube. (ie the anode or cathode current). The > > resistor will simply be supply voltage minus tube drop to give you the > > anode resistor voltage. Divide that voltage (anode voltage) by the > > desired current, to get the actual value, or close to it. Pick a real > > value made that's less than 40% away from that calculated ideal. > > > In the Philips datasheet for the Z504S dekatron, the maximum allowed > > supply voltage is 1000V. That's why you see values from 400V to over > > 600V commonly used. It really ain't that critical, as long as you > > adjust your anode resistor, accordingly. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
