The trigger should not stay on, the capacitor before the trigger electrode should only produce a pulse, unless there is a leakage current flowing to the trigger through this capacitor. You can test this by lowering the 22M resistor to ground to lets say 10M and see if the circuit behaves in a similar way, I have seen circuits with even lower resistor values down to just 2.2M. You might have to change the type of capacitor used and use a type similar to the ones in the original circuit.
There are also some small differences between the ER32 and the Z660W that you use that might affect the circuit, the Z661W is a closer replacement according to the RFT databook. /Martin On Sunday, 16 February 2014 12:25:34 UTC+1, bob harper wrote: > ok i have checked all the resistors around this tube and replaced all caps > still no good...i have doing a bit of reading cold cathode tubes my dance > and circuit design by neal [free book downloads] and it seems to me that > this circuit would need a pulse to fire and be extinguished by the 16uf cap > charging, but with a permantly live trigger this cycle would repeat > [exactly what its doing] which will not do the tube much good as the > trigger voltage should be removed before the anode voltage [if i read it > right] so i think either the diagram is wrong [unlikely] or the switching > on the jukebox has been altered/bodged i thought about using the switched > live K3 to feed a relay and timing capacitor to give a pulse to the tube > unless there is a way of again using a capacitor in the trigger circuit to > charge up between the trigger and cathode to give them the same potential > while the tube is in the conducting state.....bob > > On Saturday, February 15, 2014 4:35:23 PM UTC, bob harper wrote: >> >> hi Martin thanks for the reply yes I did tie the triggers together and >> replaced the 16 if cap will double check all the other components and check >> the anode current thanks bob >> >> Sent from my HTC >> >> ----- Reply message ----- >> From: "Dekatron42" <martin....@gmail.com <javascript:>> >> To: <neoni...@googlegroups.com <javascript:>> >> Subject: [neonixie-l] Re: trigger tube equivilents >> Date: Sat, Feb 15, 2014 12:32 >> >> Did you wire both trigger electrodes together, the Z660W have two trigger >> electrodes but the ER32 only one. >> >> You must also check that the minimum anode current is 5mA as the Z660W >> might otherwise work unreliably in some situation according to the >> datasheet. >> >> You might also have to check the capacitor connected to the anode as well >> as the anode resistor as those form the circuit that extinguishes the >> trigger tube, turning it off, and if they do not work properly the tube >> might not be fully extinguished and then it will turn on again - the >> capacitor might leaky opr any of the other capacitors/resistors surrounding >> this trigger tube might be leaky or having the wrong value. >> >> Also don't forget to replace resistors with types that can handle the >> voltage in these circuits, many cheap resistors sold today only tolerate >> 125V or 250V which won't do in circuits like these! >> >> /Martin >> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "neonixie-l" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/neonixie-l/DfIGLpwsuMk/unsubscribe. >> To unsubscribe from this group and all of its topics, send an email to >> neonixie-l+...@googlegroups.com <javascript:>. >> To post to this group, send an email to neoni...@googlegroups.com >> <javascript:>. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/bb6e19d6-a886-49b9-afdd-cfbc553c7821%40googlegroups.com. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/5e735dbe-0b02-451a-9d4e-717d1bd7ec40%40googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
