34459Re: [beam] H_Bridge
- Mar 9, 2003I have build and tested the MOSbridge 2 circuit and I am happy to report it
I used 2N3904/6 instead of PN2222/2907 driver transistors, 2.2K resistors
and some "free" Dpak N channel and P channel mosfets had I liberated from a
surplus harddisk IDE control board. The motor supply was 12V and the logic
The circuit is quite efficient with PWM 0%-100% up to 5kHz. I briefly tested
at 50kHz PWM but got significant ringing above 500mA, so I backed off but
will investigate higher frequencies later. The anti-shoot through circuit
seems to work well, and from o'scope observations breaks motor current for
about 5usec before making. The rise and fall times of the winding voltage
waveforms were a modest 2usec. Surprisingly PWM was most efficient with one
input grounded. The MOSfet internal diodes were used for freewheeling. No
heatsinks were used for the MOSfets and the circuit remained cold while
switching a 1A motor load. The voltage drop was as expected for the device
Rdson specs. I expect, with better MOSfets, 18V motors and >10A currents
can be efficiently controlled with this simple circuit.
----- Original Message -----
From: "Wilf Rigter" <wrigter@...>
Sent: Monday, March 03, 2003 6:08 PM
Subject: Re: [beam] H_Bridge
my favorite version of all: the general purpose >>> MOSBridge2 <<< design.
Use logic level MOSFETs for applications requiring up to 9V motor supply.
Use normal MOSFETs for motor supplies in the 10V - 18V. Higher motor supply
applications will require some protection of the MOSFET gates.
High logic level input signals can be anything between 2V to 24V. If
necesary add a base emitter resistor to the PN2222 to increase noise
immunity for the low level logic signal.
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.459 / Virus Database: 258 - Release Date: 2/25/2003
- << Previous post in topic