Ultimate protection : 2 x Dtap ?

hello,

some batteries have now 2 x d-tap connectors. So if using one for bmpcc and second fo monitor, are we protected?

Use a Dtap splitter.

to avoid burning the HDMI output

to avoid burning the HDMI output

For that, I would go with batteries that are recognized and have a good track record or get an IDX batter plate. That way, you are sure the power is regulated, or, as someone suggested, a splitter that also has its own circuitry to protect your camera/monitor.

If the technical specs for the battery indicated both D-taps were regulated voltages, that should be safe.

to avoid burning the HDMI output

Yes

If the technical specs for the battery indicated both D-taps were regulated voltages, that should be safe.

I will check if the outputs are not simply put in parallel. If not I will have a look to a decent spiltter.

Thank you guys for your answers

Does regulated voltage help? If you don't use the correct connection "protocol" you can still get a ground loop over SDI/HDMI, right?

Does regulated voltage help?

I wouldn't think so. Regulated just means that the battery is going to shut off when it reaches a certain threshold like 11v. Even a regulated Dtap is capable of 100w of current which is more than enough to fry a poorly designed SDI driver.

Good Luck

Right. I also don't understand how a splitter would help. From my understanding it would have to use galvanic isolation between the outputs in order to avoid ground loops. Maybe they do, but just buying "a splitter" without any further information sounds unsafe in this context.

Hmm, thinking about it, wouldn't the isolation have to be in the video cable?

Isolation of the power ground is what you don’t want. If the positive makes connection first then the current will take the next available path to ground in order to complete the circuit, that could be the camera chassis or the bnc (coax) shield. Isolating the power ground is basically forcing the voltage to take another path to ground.

Galvanic isolation of the signal is safer but still not fullproof as the bnc terminals are often chassis grounded on both sides of the isolator. You can have signal isolation but the bnc connector is connected to the monitor chassis, which is connected to a clamp, connected to a cage, connected to the camera, connected to the battery.

Anectdotally I work in a 12G studio where the “SDI protocol” doesn’t exist, we have hundreds of 12G SDI devices and ports that never seem to care about the power/connection sequence, in fact it would take hours if not days to repatch the 100s of connections necessary to follow the “protocol” everytime we turned the lights out.

Good Luck

Ah, thanks.

If the positive makes connection first then the current will take the next available path to ground in order to complete the circuit, that could be the camera chassis or the bnc (coax) shield. Isolating the power ground is basically forcing the voltage to take another path to ground.

This problem also affects HDMI?
if we create equipotentiality between camera and monitor by connecting the cage to the minus of d-tap, does this provide protection?

This problem also affects HDMI?

To a lesser extent yes.

if we create equipotentiality between camera and monitor by connecting the cage to the minus of d-tap, does this provide protection?

No, once any device is connected all commons, chassis, audio, and video connections are sharing a ground. The problem arises when connecting a second device as now all the grounds are common. The safest practice is to use discrete batteries for each device.

Good Luck