I tried varying it with absolutely no effect. It runs perfectly at 5v with the capacitor moved to the other side of the resistor. However I was clocking slowly. It may not run at spec speed. I seem to remember reading of using 5 to 8 volts for the logic. The data sheet shows the following which I'm inclined to believe. I will try Ck directly on the pins tomorrow. Someone must have tried this circuit. [image: 8453 Cct.JPG]
On Wed, Feb 10, 2021 at 11:12 PM gregebert <gregeb...@hotmail.com> wrote: > I suspect the differential voltage between lit vs non-lit numerals is too > low. The CMOS device is basically driving grids to determine which cathode > will be illuminated. I've seen similar behavior with an A-101 dekatron. > What voltage are you using for VDD ? Is it 8V as indicated on the > schematic, or a more-conventional 5V ? > > On Wednesday, February 10, 2021 at 7:22:25 PM UTC-8 bung...@gmail.com > wrote: > >> I think you are wrong. The literature explains this tube is designed to >> be driven by 5v logic and it does work. The steering electrodes are close >> to the Anode voltage which is grounded and only 5v pulses (square waves) >> are needed. Note all the cathodes are connected together internally. >> I got to thinking about the C1 position. The data sheet shows it per my >> schematic and I can't believe they made that mistake several times >> including the hand drawn notes of the designer. I think maybe I needed to >> have C1 directly on the socket pins and will try that tomorrow. >> Thanks for your interest though but you are thinking Nixie Tubes, this is >> a special tube with steering electrodes.. >> >> >> On Wed, Feb 10, 2021 at 9:42 PM chuckrr <chu...@all2easy.net> wrote: >> >>> That schematic is so wrong in so many ways. You need high voltage >>> transistors operating the tube cathodes. >>> >>> You need high resistance drving the transistor bases. You need a >>> buffer such as 4049 or 4050 driving the >>> >>> resistor, which in turn drives the transistor base. Only then would I >>> dare to use the 4028....to operate the buffer, which in turn operates the >>> >>> transistor base via appropriate high resistance. That is the only sure >>> fire way I know of to attain noise-free performance from CMOS logic >>> >>> driving cold cathode tubes. That schematic there is a noisy deal. >>> >>> >>> >>> >>> >>> ---- Original Message ---- >>> From: "peter bunge" <bung...@gmail.com> >>> Sent: 2/10/2021 8:15:21 PM >>> To: "neonixie-l" <neoni...@googlegroups.com> >>> Subject: [neonixie-l] 8453/Z550M erratic >>> >>> Using the schematic from the data sheet >>> [image: 8453 Circuit.jpg] >>> This works with the count moving around but other numbers flash >>> erratically, especially close to the number that is supposed to be lit. >>> *When I moved the bottom of C1 to the other side of R1 it works >>> perfectly. It is rock steady and does not care about line voltage or the >>> 5v supply (shown above as 8v but used at 5v)* >>> If this is an error it is continued through all the documentation and is >>> consistent. Changing the value of C1 up and down by 10 had little effect >>> but a smaller C1 helps a bit. My Rst are all directly on the socket pins >>> and the wires are all about 5 inches long. >>> I have varied the line voltage with little effect. >>> Any suggestions??? >>> >>> -- >>> 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+...@googlegroups.com. >>> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/b996ef0b-edbb-4c77-8ec1-57255dd58a82n%40googlegroups.com >>> <https://groups.google.com/d/msgid/neonixie-l/b996ef0b-edbb-4c77-8ec1-57255dd58a82n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >>> 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+...@googlegroups.com. >>> >> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/202102101842701.SM05295%40ADT-IM1 >>> <https://groups.google.com/d/msgid/neonixie-l/202102101842701.SM05295%40ADT-IM1?utm_medium=email&utm_source=footer> >>> . >>> >> -- > 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 view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/9543e23e-ebb0-46e7-8624-ddcf4a843667n%40googlegroups.com > <https://groups.google.com/d/msgid/neonixie-l/9543e23e-ebb0-46e7-8624-ddcf4a843667n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAFxqQoK_ma8wLmrAEUGOOVc018w1AOR3C4nxDd2TDbq%2BoU6C8A%40mail.gmail.com.
