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<blockquote data-quote="scottjoh" data-source="post: 448464" data-attributes="member: 20804">That won&#039;t work.&nbsp; There needs to be a guaranteed dead time between turn off and turn on of the other device.&nbsp; Simple cap/resistor circuits won&#039;t work and are not reliable enough.&nbsp; Plus an inhibit or disable during power up and power down is needed.&nbsp; Oh, one other thing. The standard H-Bridge shown in post #143 above uses both NPN and PNP transistors which can be easily replaced with N-ch and P-ch MOSFETs.&nbsp; This isn&#039;t a problem except that the Infineon MOSFET that I mentioned earlier is an N-channel.&nbsp; Typically P-ch MOSFETs aren&#039;t nearly as good as N-Ch one.&nbsp; The On resistance (Rds on) of the best P-channel device in the same package is almost double.&nbsp; To make the high side and the low side symetrical engineers typically use N-ch MOSFETs in place of the P.&nbsp; The problem then becomes the gate of the high side MOSFET must be 10 volts higher than the drain to turn it on fully.&nbsp; Under normal car electronic conditions the drain will be up to 14.4V.&nbsp; So now a some kind of power supply is needed to get that extra 10 volts to ride on top of the high side FET drain.</blockquote>

[QUOTE="scottjoh, post: 448464, member: 20804"] That won't work. There needs to be a guaranteed dead time between turn off and turn on of the other device. Simple cap/resistor circuits won't work and are not reliable enough. Plus an inhibit or disable during power up and power down is needed. Oh, one other thing. The standard H-Bridge shown in post #143 above uses both NPN and PNP transistors which can be easily replaced with N-ch and P-ch MOSFETs. This isn't a problem except that the Infineon MOSFET that I mentioned earlier is an N-channel. Typically P-ch MOSFETs aren't nearly as good as N-Ch one. The On resistance (Rds on) of the best P-channel device in the same package is almost double. To make the high side and the low side symetrical engineers typically use N-ch MOSFETs in place of the P. The problem then becomes the gate of the high side MOSFET must be 10 volts higher than the drain to turn it on fully. Under normal car electronic conditions the drain will be up to 14.4V. So now a some kind of power supply is needed to get that extra 10 volts to ride on top of the high side FET drain. [/QUOTE]

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