Think you might come out with a kit?
Michail Wilson 206-920-6312 From: [email protected] [mailto:[email protected]] On Behalf Of Mike Mitchell Sent: Monday, December 24, 2018 9:29 AM To: neonixie-l Subject: [neonixie-l] Re: OT - ElectroMechanical 7-seg clock On Sunday, December 23, 2018 at 3:37:00 PM UTC-5, Terry S wrote: I like it Mike -- care to share your design? Terry When I saw the https://imgur.com/a/E98sq posting I contacted "iamatesla" and asked about a kit. I also asked about through-hole instead of SMD. Those conversations didn't lead anywhere, so I examined his schematic and came up with my own design. Rather than using individual MOSFETs for the H-bridge drivers, I settled on the L293D quadruple half-H drivers. I multiplexed the displays in standard segment/digit fashion, so I only needed four chips, two for the segments (7 half-drivers) and two for the digits (4 full drivers). Multiplexing also means adding 56 diodes, as the solenoids are bi-directional and not uni-directional like LEDs. The solenoid pulse lasts only a millisecond, so the diodes have to have a fast recovery time and be able to handle the inductive transients. I used these: https://www.vishay.com/diodes/list/product-88736/ I split the clock into two boards to fit better in a case. One board has all the drive electronics, including an off-the-shelf 5v to 19v DC-to-DC converter. The second board has a Teensy 3.2 processor, a bluetooth module, two eight-bit shift registers, a 3.3v to 5v level shifter, and connections for a GPS module. I didn't put the GPS module on board because I'm using its patch antenna and I didn't want the display board to block the signal. The GPS module sits above the display board. I've done enough of this type of work that I didn't draw out the schematic for the teensy, GPS, and bluetooth connections. I'm including a photo of a partial driver board schematic and some other photos of the construction. If you look at the photos you can tell that I built two of these clocks. I'm happy to answer any questions. Mike Mitchell -- 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 email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/a43f091a-951e-4f99-8db0-c74e0e56a212%40googlegroups.com <https://groups.google.com/d/msgid/neonixie-l/a43f091a-951e-4f99-8db0-c74e0e56a212%40googlegroups.com?utm_medium=email&utm_source=footer> . For more options, visit https://groups.google.com/d/optout. -- 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/00f401d49bf8%24a1937fe0%24e4ba7fa0%24%40com. For more options, visit https://groups.google.com/d/optout.
