J
John Fields
Guest
On Wed, 24 Nov 2004 12:03:22 -0600, "Stacy" <stacy@123.com> wrote:
---
For your circuit, if the load is an incandescent lamp there's no need
for the 2.2k or the 10k resistors or the capacitor, since what you
have is what's called a "static switch" and you have no need for phase
control.
I think van Roon was confused and wanted to use the 2.2k and the 0.1ľF
as a snubber. Take a look at
http://www.littelfuse.com/data/en/Application_Notes/AN1007.pdf
for some circuits that work.
--
John Fields
"John Fields" <jfields@austininstruments.com> wrote in message
news:1nb9q0pcsajomc41481ubirig7k6qjhs1s@4ax.com...
On Wed, 24 Nov 2004 09:16:05 -0600, "Stacy" <stacy@123.com> wrote:
I have built a circuit based on. It uses a Triac and a Optoisolator 3031
to
turn power on.
http://www.uoguelph.ca/~antoon/gadgets/relays/relays.html Solid State
Relay
by Tony Van Roon
I hope that someone can answer a few questions ( If you could be simple
on
your explanation as anything involved with get me lost)
1. The circuit I thought is suppose to be a Latching circuit. That is,
from
my understanding, you apply the 5vDC for a second and the 120 light will
turn on. When you remove the 5v DC the 120 Volt light stays on. This does
not work for me. The 120 Volt light stays on only when I keep the 5 v DC
applied. When I remove it the light goes out.
---
That's the way it's supposed to work. When you remove the 5V you are
no longer supplying current to the LED in the opto, which disconnects
the TRIAC's gate from its trigger source, the mains.
---
2. The circuit does not work when I have the .01uf capacitor connected
as
shown in the schematic. That is, the light simply comes on and stays on.
This is regardless of the 5 v DC.
---
Make sure you have the capacitor connected to the junction of R3 and
R4 _only_, and that the gate of the TRIAC is _only_ connected to R5
and IC1-4. The "hump" in the wire connecting C1 to R3 and R4 means
that it jumps the wire it's crossing, not that it's connected to it.
---
Can anyone help me to understand. Or perhaps if the circuit is wired up
as
described its suppose to exibit these symptoms ?
It frustrates me as Im trying to learn that I think I have done all the
right things, but then it doesnt work.
---
Not to worry; we (me, anyway) all learn by trial and error.
--
John Fields
Thanks John, I'm glad it works sorta the way it is suppose to. I think I
have read about 5 or 10 of similar circuits and some of them they call them
latching. I must have had that confused.
Yes the "hump" is NOT connected. -thanks.
When you say
Make sure you have the capacitor connected to the junction of R3 and
R4 _only_, and that the gate of the TRIAC is _only_ connected to R5
and IC1-4.
I do have the Cap between R3 and R4. From there the cap is connected to a
common line that has the R5 / MT1 and load connected up to it. (bread
board).
4-------Gate
|
.01u R5 MT1
|______|_____|______(Load)__
---
For your circuit, if the load is an incandescent lamp there's no need
for the 2.2k or the 10k resistors or the capacitor, since what you
have is what's called a "static switch" and you have no need for phase
control.
I think van Roon was confused and wanted to use the 2.2k and the 0.1ľF
as a snubber. Take a look at
http://www.littelfuse.com/data/en/Application_Notes/AN1007.pdf
for some circuits that work.
--
John Fields