Doing an RS order today.... don't you just love it when they only sell the H11AA1 in tubes of 50....
AliExpress here I come again
Also... not in SMD? Odd.. means its the only DIP part on my board. Maybe I need to look harder
There certainly exist other AC to DC optocouplers, and I expect you to be able to find them in SMD packages as well, like SMDIP. This is just one example, which I happen to have on hand and have used before.
R1 and R3 in the above schematics indeed need to be 1/2W versions. At 30V they dissipate some 380 mW.
Thanks. Just marvelling at the OUTRAGEOUS prices of 1/2w resistors on RS. Plus, the selection of resistors you can purchase in reasonable quantities have disappeared. I don't want 500 of em!
Much as I HATE AliExpress.... nearly everyone on Ebay is basically an AliExpress reseller anyway, so looks like good ole China will be getting the order. Then it's 'will it be knock-off' or decent time again.
Digikey, Farnell, RS etc just have silly min orders now for us hobby folk.
I didn't realize how good hobbyists have it here in the USA.
For example, that part is $1.30 in singles from DigiKey here and I realize that if I just want 1, paying $6.99 for shipping would be silly. However, I could buy 10 of them for just $1.50 each including shipping and have some in stock for next time.
Or, put 2/3/4 lower wattage resistors in series. Just divide up the resistance desired, and of course don't place them too close together. BTDT. It ain't pretty, but gets the job done.
And with SMD parts, probably not even that ugly.
Well... I will probably do what I end up doing...
AliExpress some questionable part... prototype it, and then when happy, buy decent ones from somewhere reputable
OK.... Cheeky maybe, but still another LED question (on the same project).
This unit some some god-awful looking neons on the input of the mains (115v-265v AC).
Best way of running a 5mm led off that? I looked for some 230v (ideally wider range than that) LEDs and had to sit down for 10 minutes at the price.
Plus, they were pretty sizeable (in depth). If I could put the reduction components on the PCB, I could reduce the LED panel size.
Maybe...
Looked through RS and Digikey for led panel indicators. There are some, but none with a 115v - 230v input range. Maybe asking too much then
OOh... Larry... Interesting (shame the first one is now listed as obsolete on Digikey). Must be a newer version around
Yes I saw those Emily. Thanks for looking!
IL250
About 4,500 in stock at Digikey.
I just found that IL250 Larry... thanks.
Just need to exactly dial in the components I need now.
Thanks for all the suggestions folks
Am I having a sudden brain backfire....
My opto-isolator is 5v. The opto-isolator driving LED anode is at 5v, and I am driving the cathode with the output of my 3.3v processor (from a serial pin). I am correct in assuming that is OK?
That will not affect the processor, as I am supplying a ground signal.
My brain hurts today
Can you draw a schematic of what you are trying to do?
What you described makes no sense.
Isn't the Teensy a 3V device ?
Yes. But, my original question was that I thought that even though the serial transmission is from a 3.3v device, would it be OK to have this driving a LED that has it's anode connected to 5v?
The system works now with the anode connected to 3.3v, but just odd it didn't either go zap or work when it was connected to 5v.