One component 5A H-Bridge hooked directly to prop?
eagletalontim
Posts: 1,399
I am in the process of redoing the entire solar panel tracker circuit as most of it is just thrown together from bits and pieces of other projects. It works for the most part, but has a few issues. One of them is noise from the relays clicking off that are setup as an H-bridge. There are 2 of these as I have 2 separate motors.
What I am attempting to do is design a full circuit board that has all the features built into it as I already have including a few extra. I will be limited on space so I need to minimize large components. I will be using a 40 Pin DIP Prop so it can be replaced if a failure happens without having to unwire the entire board and unsolder the old Prop.
So, to get to the point... I have located this H-Bridge and was wondering if it would be safe or possible to run this component directly from 2 Prop pins without an other components : http://www.infineon.com/dgdl/Infineon-TLE5206_2-DS-v01_01-en.pdf?folderId=db3a30431b3e89eb011bb632994f065b&fileId=db3a30431f848401011fc753a71779a7&ack=t
What I am attempting to do is design a full circuit board that has all the features built into it as I already have including a few extra. I will be limited on space so I need to minimize large components. I will be using a 40 Pin DIP Prop so it can be replaced if a failure happens without having to unwire the entire board and unsolder the old Prop.
So, to get to the point... I have located this H-Bridge and was wondering if it would be safe or possible to run this component directly from 2 Prop pins without an other components : http://www.infineon.com/dgdl/Infineon-TLE5206_2-DS-v01_01-en.pdf?folderId=db3a30431b3e89eb011bb632994f065b&fileId=db3a30431f848401011fc753a71779a7&ack=t
Comments
If you look at section 3.3 in the dataheet you will notice the VinH symbol with a minimum threshold of 2.8V for a logic high so the Prop will drive this easily. Just for that extra protection you could allow for a resistor from the Prop pin and 10k should be fine. However the H-bridge doesn't allow for freewheeling as there is control to disable the outptuts, they are either forward, reverse, or braking, so you will not be able to PWM but this might not worry you.
You should allow for pull-downs or even pull-ups on your two I/O so that the motor does not try to run when the Prop pins are floating as would be the casse during reset or lack of software control.
5A continuous with solid heatsinking, note, as it has 0.2 ohm DMOS drivers, meaning 10W dissipation.
[ Oh yes, I also just noticed it has very slow high-side switching so only low frequency PWM is sensible. But if you
were using relays before, not an issue. ]
One big issue I am having with the relays is noise / flyback voltage being picked up by the sun position sensor. This is why I am trying to switch to a "1 component" solid state controller. I believe it will help me reduce the noise from the motors. Just a design flaw I had from the very beginning.
There might be a spike from the relay when it turns off but otherwise it is just an electromagnetically operated switch, in other words, a switch, so it doesn't generate noise when it is open or closed. The noise you are getting is from the motor's commutator, it is constantly making and breaking, arcing and sparking, so your H-bridge won't help there. It's possible that if you mount the H-bridge with the motor that you can limit the EMI from it but you would probably also need some filtering on the supply as well. Otherwise you may need shielded cable to the motor or wrap the feed wire around a ferrite core a few times will help too. Hard to say exactly what to do from this vantage point but DC brushed motors are very noisy electrically speaking.
What are you using for the sensor and how is it connected etc.
Once again, the more details you provide freely, the more help that is freely available. Don't wait to be asked to provide every little detail bit by bit, it's too painful for all parties involved.
Why not just turn the sensor off during movements, do a move, stop, turn sensor back on, repeat if needed.
A relay should be fine, if it changes with no-load.
I'd be inclined to use a relay to reverse (flyback?) and use PWM/DC soft start - which can now be single ended, not H bridge, and so opens up Switching regulators as the Motor drivers.
Soft start reduces shocks in the system, and saves energy.