Solid-State Relays for Switching?

[tictac]

Just wondering if anyone is using solid-state relays for switching in an ODS circuit instead of mechanical relays. If so device part numbers and schematic would be interesting to see.

My AC Electronics class topic for this week is "Transistors used as switches" so I wondered if anyone was into this kind of thing...

TT

[ChrisM]

I have used transistors along with CMOS to switch mechanical relays before. Guess that's not much help though.

The transistor was a driver/switch.

[DonMoose]

I sorta thought the International Rectifier PVT series might be worth fiddling with ... if they still make them.

Capacitance across the output side in OFF mode was 12pF - at tube impedances that might be enough to fail to turn 'off' enough in either series or shunt mode (tone suck).

[glasman]

I pondered the idea of using solid state switching a few years ago. One of the problems that you run into is signal level. The "standard" SS relays with a low "on" resistance are limited in signal swing. You can't exceed the supply voltage for the device. The output from the tone recovery amp would blow it out of the water. If you are running low voltages, say +/- 15V, the 5043 analog switch is the nuts. I have worked on a ton of servo systems that use these for switching.

Another option would be to use Perkin Elmer optoisolators. The problem I saw with these is that the off resistance was not that great (<50Meg) and the switching response was kinda funky.

[paulster]

Another option would be to use Perkin Elmer optoisolators. The problem I saw with these is that the off resistance was not that great (<50Meg) and the switching response was kinda funky.

Also, which is a consideration for you, the RoHS status is indeterminate. Mesa continue to use them despite the exemption expiring and Perkin Elmer have ignored my requests for information on the RoHS compliance status of their product.

[glasman]

Another option would be to use Perkin Elmer optoisolators. The problem I saw with these is that the off resistance was not that great (<50Meg) and the switching response was kinda funky.

Also, which is a consideration for you, the RoHS status is indeterminate. Mesa continue to use them despite the exemption expiring and Perkin Elmer have ignored my requests for information on the RoHS compliance status of their product.

Yes I saw that as well. Never got past the spec sheet with them. It was just one of a few dozen options I looked at when considering non-relay swithcing. In the end I stuck with RoHS complient relays .

[tictac]

Mechanical Relays keep looking better and better, at least for the ODS type amp design...

TT