[time-nuts] Re: 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor "Continuous Operation" ?

[jack.davis]

You might try a 2N5060 scr.Sent from my Verizon, Samsung Galaxy smartphone by Morse code.
-------- Original message --------From: ed breya <eb at telight.com> Date: 10/10/21  3:36 PM  (GMT-08:00) To: time-nuts at lists.febo.com Subject: [time-nuts] Re: 5065A - Replacement of A14CR13 (Logic Ass:y) Thyristor "Continuous Operation" ? The CR13 can be almost any small SCR, like in a TO-92 size. I happen to know of one offhand, because I just yesterday used it in the Z3801A project, for the same type of function - latching the state of the indicator. I have a bunch of these in the thyristor department, and looked up various ones until I found this particular part was about right.https://datasheetspdf.com/pdf-file/284595/UnisonicTechnologies/XL1225/1This is an oldie. Another classic one is the C103 SCR. There should be plenty of modern little SCRs that will do. If nothing seems right, you can always make your own equivalent from a PNP and NPN Q tacked together right - but two parts are needed, and possibly an extra resistor or two, so it would be kind of a kludge.For an SCR, the main things are gate current sensitivity, trip (latching) anode current, and holding current.BTW in my Z3801A project, the SCR holds the "power on" state, but I drive the lamp the opposite way. It stays off in normal operation, and lights amber to warn that AC power has dropped out in the past - simply because I have plenty of a certain style amber lamps, but only one green (for lock). The reset button trips the SCR back on, and the light goes out.I found the circuit wouldn't latch at first - I had made the anode current only about 1 mA, well above the holding current, but the trick is you need the available trip current to be high enough to go, then it holds down to much lower amounts. Changing to a smaller resistor made it work.Ed_______________________________________________time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send an email to time-nuts-leave at lists.febo.comTo unsubscribe, go to and follow the instructions there.