detector.
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I saw that. Might want to add 1M or something like that between line and neutral, for discharge.
Assumptions have sunk many a ship :-)
But you'd still have one left over. What a waste of resources there :-)
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Why bother? The OP asked for a zero-crossing detector. Allusions to opto-coupling indicates he has a transformer-isolated PS, so that primary will dump any "Darwin" current ;-)
Did you read the thread, or do you just like to ramble ?:-)
Transformers are unreliable for accurate zero-crossing timing. ...Jim Thompson
-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 |
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Decades ago there were iffy 741 opamps coming in, so we had to test them prior loading into boards.
I made a little 2 opamp triangle wave oscillator with LED, if a new opamp work in the integrator section it was okay, but if a bad opamp worked as a comparator, we binned separately them for that use ;)
Ones that could do both were binned to make up for the others.
Can't remember which brand they were, probably the cheapest available. Didn't use a separate comparator chip, & response time didn't matter.
Grant.
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The first switcher I ever did, hysteretic 24 to 5 volts buck, used an uncompensated uA709 as the comparator, feeding a 2N2905 and then a
2N3055. A 709 was an OK comparator. The 3055 was reasonably fast because it ran as an emitter follower, unsaturating. I ran it at 24 KHz because I could hear 22K in those days.I recall that a uA709 needed three external compensation parts to work as an opamp. It had some nasty latch modes, too.
We got a lot of bad parts in those days, especially RTL and TTL. We rarely get a bad IC any more.
John
[snip]
There IS a discharge path, without any additions.
Buy a cooler, you need the lesson ;-) ...Jim Thompson
-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 |
"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...
This doesn't provide accurate zero crossing because of the phase delay introduced by the capacitor and resistor (C1 and R1). That phase delay will change with frequency and will vary with voltage. Unfortunately I need between 30V and 160V AC and between 200Hz and 600Hz oherwise this could have worked - the problem is using a capacitor to limit current and the phase delay that creates.
Forget that! This would be tru if you used the neutral as the input, but it actually uses the hot line I forgot to look at the timing diagrams on the second page :(
ROFL! Darwin current, classic! That was a good one.
I did read the whole thread and other than a transformer with too high a voltage I don't remember anything. You'd you be looking at yet another power supply.
Not if they are wideband enough. Check out the Triad Magnetics stuff.
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Nope, upon a disconnect C2 dischargeth not. Well, except across the Darwin path you mentioned before ... bzzzt ... OUCH!
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
Sorry you loseth ;-) ...Jim Thompson
-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 |
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