Interlock on fb3-SE ?

[mccarrot]

Remember a solid state could fail shorted, and you need to have a big heatsink on it because you have to switch minimum 5 Amps/5V

[dave]

You certainly wont need a heat sink on a solid state relay if its only switching 5A!!! 50A, maybe a different story!

[edison]

I will break the circuit in the 230V before my powersupplies. The benefit of the solidstate relais that is not a mechanical thing.

Also i can mount the solidstate flat on the board so that safes room. I made 4 outputs for my 4 powersupplies so i dont have to loop the 230. every powersupply is connected to this board.

If you have an idea to take over the second transistor let me know. I can finish the layout today so we have to board ready next week.

[mccarrot]

Cutting the 230V is not preffered, in my RGB I cut the 230V, but my lasers keep lasing for short period until the PSUs are discharched.

My galvo's even stops earlyer than my lasers so I have a static beam for a short period

sacrificing safety because it easyer to wire is not correct.

cutting the 5V to the driver is the way to go.

Here is a link to a document Bill Benner made. this is how you should do it.

http://www.pangolin.com/resguide12.htm

[edison]

maybe its was better to only switch of the 5v and not the 24v +- At least your scanners are still moving.

[edison]

If anyone has a suggestion to overtake the second transistor here ,s the schematic:

[buffo]

The link I posted above was to a generic interlock circuit. But as Mccarrot pointed out, this generic circuit does not allow for a remote start button.

The circuit I use in my projector actually looks like this. And as you can see, it does allow you to start the projector from either the remote box or locally at the projector. Note that the circuit doesn't show a few additional elements, such as the power-on delay circuit and the local emission indicator, but it is complete enough that you should be able to follow how it works.

For a detailed explanation of how the circuit works, see the middle of this post, where I'm explaining it to taggalucci.

Adam

[mccarrot]

I think its not possible to use a power transistor to switch on/off the 5V as you always have a voltage drop over the transistor

A Fet could work.

[dave]

Better yet, use a shutter?

[mccarrot]

I prefer switching off the power to the drivers, this way you have a faster switch off, its easier to implement, it's cheaper and I think a relais is more reliable than a shutter but I may be wrong.