Die4Drive (low side drive) and red diodes (high side can)

[Zoof]

When the case of the red diodes is connected to 5v and not electrically insulated it gives some inconvenience in isolating the red module from the projector's base plate that is grounded.

To circumvent this, can we not simply connect the drivers high side to the base plate (0V) and connect the driver's low side to a -5V supply? The driver still sees a 5V voltage supply and the case of the red module will have the 0V base plate potential, eliminating the need for electrical insulation.
I don't see a problem with this.

It introduces an inconvenience with the modulation signal (0 to 5v) which will be 10V higher than the -5V low side of the driver.
How can we bring the modulation signal in the -5v to 0V range? or will it introduce a bigger hassle than isolating the whole module from the base plate?

thanks,
Matthijs

[andy_con]

just a thought but wouldnt it be easier to insulate each diode.

saves lots of messing around with the driver etc

[dave]

How can we bring the modulation signal in the -5v to 0V range? or will it introduce a bigger hassle than isolating the whole module from the base plate?

It would be menial to offset the modulation signal. Nothing that cant be done with a opamp or 2

Nice idea BTW!

[dave]

just a thought but wouldnt it be easier to insulate each diode.

Personally having messed around insulating the diode the way Simon and you do it, I am over it. I honestly don't like working with glues that come with carcinogen warnings..

[andy_con]

Personally having messed around insulating the diode the way Simon and you do it, I am over it. I honestly don't like working with glues that come with carcinogen warnings..

i was suggesting that as such, just didnt know if using some of the tapes and thing people use would be easier.

but if modding the driver as such works then great please post details as im interested.

[drlava]

I don't think it would work as you describe. It could be wired this way with additional modulation offset correction, however the diode anode would be connected to 0V and the cathode (the case connected pin) would now be below 0V, not at 0V. This is a less dangerous situation, but still requires diode isolation. The other solution is to just use a high side driver, there have been a few posted including the FlexMod P3.

[dave]

Actually, nope, that wont work as the diodes case is cathode, not anode.. Just use a high side driver like the new P3 or Andy's driver..

[Zoof]

quite right, it won't work, thanks for pointing that out....

[mccarrot]

Hi Zoof,

Johan, (Edison) got 4 of andy's highside drivers from me. Now he received the 6 ch RBLD driver with tec he will not be using the boards anymore i quess.

You can buy some of those drivers from me for cost price.

regards,

Maurice.

[edison]

i still use one. I will pay the one that i use now. Let me know what the price what i have to pay for that one so i can send the other ones directly to zoof. if he wants the drivers.