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sinara-hw / DIO_SMA

DIO_SMA 8 channel isolated digital input/output EEM
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TTL SMA isolation from front panel #2

Closed sbourdeauducq closed 5 years ago

sbourdeauducq commented 6 years ago

In each SMA-DIO the two banks are supposed to be galvanically isolated, but the grounds of the SMA connectors are shorted by the front panel. ttl_sma_insul

gkasprow commented 6 years ago

Aren't there black shrinking tubes on the SMA connector installed?

sbourdeauducq commented 6 years ago

There are, but the nuts on the SMA connectors are resting directly on the varnished metal of the front panels. Even though the DC impedance between two banks that I measured is ~200k, this looks quite fragile. I was expecting some solid plastic washer like those on Urukul.

gkasprow commented 6 years ago

The front panel label is not conducting. 200k were placed intentionally to discharge potential ESD. Plastic washers dont fit. I couldnt find smaller ones that used in Urukul.

hartytp commented 6 years ago

I couldnt find smaller ones that used in Urukul.

I thought you were planning to 3D print these. Or did that work out too expensive?

gkasprow commented 6 years ago

I did dedicated one for Sayma RTM. For SMA IO it's too expensive and the heat shrink tubes seem to work well.

hartytp commented 6 years ago

@gkasprow Sounds good. I was just curious!