[neonixie-l] 7 Segment Common Anode Display
Hi Folks, Hoping the group can help. I built an eight 8 clock using 2 savaged 4 digit bedside alarm clocks. I am using a multiplex method to support the display. The multiplex is based on a design provided by David one of this group's members and consists of a 74HC595 SPI 16 shift register and a 74HC245 Octal tri-state transceiver register set in pairs, with 22 ohm resistors in series with the 7 segments plus decimal point, the other pair powers the 8 anode power lines. The system is currently running at 5V from a dedicated DC-DC step down 12V-5V transformer. While the clock is working I feel that the intensity of the digits varies from one end to the other and the overall brightness could be more intense. So is there a way of increasing the brightness of each LED with a change to the circuit? Thanks for any help you can offer. -- 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/5aa7bc81-9453-46b9-9873-caee1022ad45%40googlegroups.com.
Re: [neonixie-l] 7 Segment Common Anode Display
> Here is a schematic diagram that I just whipped up. It uses the SPI signals > to shift data into the anode and cathode drivers. > The software needs to write two bytes (digit then segments) to the SPI port, > then write LOW then HIGH to the LD/ signal. You can also use an HT16K33 chip which controls both the anodes and cathodes and regulates the current so you can dispense with the resistors. It's a neat chip, and can optionally read a bunch of switches as a bonus. - John -- 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/BD194203-1160-4227-AA62-CD592D7884A8%40mac.com.
[neonixie-l] 7 Segment Common Anode Display
Hi, I am sure the group can help with this simple question. I am building a clock using 8 x 7 Segment Common Anode displays. The display uses a MAX6921AWI display driver chip and multiplexing to drive the displays. The problem is that the above chip has a minimum output of 8V, however the 7 Segment Common Anode displays are rated at 5V. This being confirmed by the testing of the displays using the 5V from an Arduino Uno via a 220ohm in-line resistor and back to ground. Each display is 55m by 38mm and has 45mm x 25mm digits, 10 pins on the rear, with WLG marked on the back, manufactured in 2008, ( these displays being recovered from two 4 digit 9V supply bedside clocks). Can I use 8V to power these displays/what is the maximum input voltage? If not then how best to use the MAX6921AWI allowing it to supply 8V while the displays receive a maximum of 5V? I am sure the above is simple to many however being new to using 7 segment displays I would appreciate any help. -- 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/6154b80f-9f51-431c-999e-54e4c91d1d65%40googlegroups.com.
