Hi,
I have made - and made work - a SSR designed by Dotor Dan a couple of years
ago. But I destroyed it (the MOC3061) - I think by reversing the load and the AC supply-, and I cant make it work again. The
problem is the MOC3061 (it lights up the load if I connect terminals 4 and 6
using a screwdriver).
I have the following values when it should light up the load:
Terminal 1: 4.99 V (I have been using 5 V for quite some time)
Terminal 2: 4.56 V
If I measure the voltage over terminals 1 and 2 I get a voltage drop of 0.43 V
from terminal 2 to terminal 1 - which is surprising!
I really can't figure out what is going on - can anyone help?
torben
Circuit diagram
It would help if you posted a link to the original article or provided a schematic of the circuit.
ssr
Hi ggallant,
I dont have web page (URL). Can I send you a PDF-file or a JPG photo?
torben
relays
You should get a reading of 0v on terminal 2 when the relay should be active. check your driver pin and make sure it changes states. you can also check the relay by disconnecting pins 1 and 2 and using a separate power supply. (ps disconnect the relay when you check the driver pin states.)
Good Luck, I am only going by what information you had in your post so forgive me if i’m way off base.
RG
ssr
Hi ggallant and robotgoldfish,
I have tried to do some calculations.
According to MOC3061’s datasheet I have:
Current 0.06 A
Power Dissipation: 0.120 w
I get that to mean that the resistance over the diode calculates to 33.3 Ohm
and the voltage drop calculates to 2 V. That leaves 3 V for the limiting
resistance - ie. that should be 50 Ohm.
I have put my last MOC3061 on a breadboard with 5 V input and 1)a 39
Ohm limiting resistance and 2) a 330 Ohm resistance. I “expected” that that
should short terminals 4 and 6 of the MOC3061 - but it did’nt.
But I got:
1) T1 to T2: 2.80 V; T4 to T6: 0.428 Ohm
2) T1 to T2: 1.19 V; T4 to T6: 2.520 Ohm
When I came back after lunch I got
2) T1 to T2: 1.90 V; T4 to T6: No connection
Do I destroy the MOC’s as soon as I solder them into place or do they
auto-destruct after a while in the breadboard?
So I am even more at a loss.
torben
You may say whoops.
I looked at the Datasheet and the Max voltage between pins 1 and 2 is rated as 1.5V you are apperently running it at 2.8v.
I also noticed the note on page 7. Please post the circuit you are trying to get to work so we don’t have to guess to help you.
RG
ssr
Hi,
Correction:
When I came back after lunch I got
2) T1 to T2: 1.90 V; T4 to T6: No connection
should have been:
When I came back after lunch I got
2) T1 to T2: 1.90 V; T4 to T6: 1.76 Ohm
No autodestruction!
torben
ssr
Hi RG,
No, I am using 330 Ohm as limiting resistance in my circuit - ie. the voltage drop over pins 1 and 2 is calculated to 1.19 V.
(see (2)
I did’nt find any (relevant) note on page 7 of http://html.alldatasheet.com/html-pdf/53872/FAIRCHILD/MOC3061/2872/7/MOC3061.html
Can I send you a PDF-file or a JPG photo?
torben
ssr
Hi ggallant and RG,
The problem is solved. It lay with the electronic switch connected to terminal 2 - where I certainly did’nt expect it.
The voltage drop from T1 to T2 is 1.18 V when the switch is closed - pretty close to the calculated 1.19 V.
Thank you very much for trying to help me.
I have noticed the difference between a reply and a comment, but I still dont know how to send you a PDF-file or a JPG photo.
best regard
torben
LMR & pictures
I find posting pictures on LMR somewhat cumbersome. There are plenty of nice write-ups that include them so it is possible. There is an icon for inserting an image. You can save files in you LMR account or on a internet host such as dropbox.
The note:
First i’m glad you found the problem. But i was of course referring to the datasheet i provided in my answer. (dated 2010 v yours dated 2003)