Customer:
I have temporarily connected a common-cathode LED display with an IC 4026 counter circuit on a breadboard. I started the chip with a counting pulse signal and everything works OK. Now I have a common-anode LED display (4 units) and tried to run it with the same chip, but it doesn’t work. Everything is connected the same way but the LED display shows garbage. Should I use the same circuit but with a different chip? The circuit was designed for this chip and for a common-cathode display. I cannot find any information about this anywhere.
Original message (Croatian)
Poštovani, Provizorno sam na univerzalnoj pločici spojio led zaslon s katodom i krug IC 4026. Pokrenuo sam čip signalom za brojenje impulsa i sve radi OK. E sad, kako imam led zaslon (4kom) s zajedničkom anodom pokušao sam i njega pokrenuti s istim ćipom ali neide. Sve je isto spojeno no led display pokazuje bez veze. Pitanje: da li da koristim istu shemu ali s drugim ćipom. Naime shema je napravljena za taj ćip i za zaslon s zajedničkom katodom. Tražim po internetu i nem nigdje. Lp, Hvala
Originally submitted via email support on 9 December 2021. Migrated to the forum for community visibility.
Soldered Support:
The IC 4026 is designed for common-cathode displays. If you need to connect a common-anode display, you must use an inverter to reverse the logic state of the signals. There are chips that contain multiple inverters inside that you can use, or you can build an inverter with MOSFETs. If you connect a common-anode display directly to the IC, you will get “-” instead of “0” or “C” instead of “1” because the segments are inverted.
Original message (Croatian)
Navedeni IC je za displeje sa zajedničkom katodom. Ako vam je potrebno da spojite displej sa zajedničkom anodom morate koristiti inverter koji će obrnuti logičko stanje signala. Postoje čipovi koji imaju više invertera u sebi te možete to koristiti ili napraviti inverter s mosfetima. Ako direktno spojite displej sa zajedničkom anodom na IC dobit će te “-” umjesto “0” ili “C” umjesto “1” jer su segmenti invertirani.
Customer:
Thank you for the quick response and explanation. These two LED displays were sold to me without me checking them first, and now I’m looking for a solution. I need a pulse counter that can count up to 10,000 pulses. In Zagreb there is simply no choice of displays. Is there any IC for this display (or counter circuit) with common-anode so I don’t waste them? I see you have various components, so I’m interested in whether they can be purchased and delivered. You also have displays cheaper than here in Zagreb. Thank you again.
Original message (Croatian)
Poštovani, Hvala Vam na brzom odgovoru i objašnjenju. Ova dva led displeja su mi prodali bez da sam ih provjerio i sad tražim rješenje. Radio bi brojač impulsa do 10 000 impulsa. Tu u Zgb-u jednostavno je nikakav izbor displeja. (Elmatis, Kronos, Chipoteka i Tevetron). Postoji li neki IC za ovaj displej (ili shema brojača) sa zajedničkom anodom da ih ne bacim. Vidim da imate razne elemente pa me interesira da li se oni mogu kupiti i dobiti pouzećem. A imate i displeje jeftinije nego tu u Zgb-u. Hvala još jednom i pozdrav, [name removed]
Soldered Support:
For common-anode displays, you need to invert the output from the 4026 so that the characters display correctly. Unfortunately we don’t currently stock any inverters, but you can find them at electronics suppliers. I’m not aware of another IC that could replace the 4026 and do the same job with a common-anode display. Everywhere, some inverter (IC or transistors) is used in combination with this application.
You can purchase by cash on delivery, but you need to place an order on the web shop.
Original message (Croatian)
Za displeje sa zajedničkom anodom je potrebno invertirati izlaz od 4026 kako bi se znakovi ispravno prikazivali. Nisam siguran da postoji drugi IC koji bi se mogao staviti umjesto 4026 i raditi isti posao samo s displejom sa zajedničkom anodom. Svugdje se koristi neki inverter (IC ili tranzistori) u kombinaciji s [address removed]. Možete kupiti pouzećem, ali trebate napraviti narudžbu na web shopu (Soldered: Open-Source Electronics, Boards, Sensors & Modules – Soldered Electronics). Za ostala pitanja oko narudžbe slobodno nas kontaktirajte te će vam korisnička služba dati sve odgovore.