Nowadays, we're trying to replicate a 24V 40A H-bridge as shown in the link: http://hades.mech.northwestern.edu/index.php/Driving_a_high_current_DC_Motor_using_an_H-bridge

enter image description here

Component   Value/Part#
MOSFETS     STP80NF55-08 (80A 55V)
Half Bridge Driver  IR2109

DC to DC converter  VBSD1-S24-S12-SIP (24V to 12V)
Regulator   78L05 (5V)
Inverters   SN74HC14N
Optoisolator    4N270545K
C_B     0.1 uF
R_G     4.7 Ω
R_PD    2.2 kΩ

Our layout: enter image description here

Before we start, we comprehend the basic principles of the H bridge. In this design, we have trouble in providing 5V into 4N27 optocoupler and 12V into IR2109 Gate Driver. The voltage converter VBSD1-s24-s12 sparks and burns each trial and we measure 24V voltage applied to IR2109. While this procedure, the motor could not move at all.

  • Near to VBSD1 converter, we use polar capacitors instead of nonpolar ones as the datasheet of it. This is true or not?
  • What can we measure to control this circuit?
  • What can be the reasons behind the converter burn?

IR2109 datasheet: http://www.infineon.com/dgdl/ir2109.pdf?fileId=5546d462533600a4015355c7e85b1679

Note: The ground terminal is the left hand side of the copper traces

  • \$\begingroup\$ 40A high current, cute :) \$\endgroup\$ – JonRB Aug 22 '16 at 13:06
  • \$\begingroup\$ Why are you using half bridge drivers AND a bridge?? You should need one or the other, not both \$\endgroup\$ – Scott Seidman Aug 22 '16 at 13:11
  • 1
    \$\begingroup\$ @ScottSeidman Two half-bridge (gate) drivers for a full H-bridge seems reasonable to me. \$\endgroup\$ – W5VO Aug 22 '16 at 14:24
  • \$\begingroup\$ @W5VO -- the half bridge drivers I know are to drive motors and such, not bridges. \$\endgroup\$ – Scott Seidman Aug 22 '16 at 14:38
  • \$\begingroup\$ 2 half-bridge drivers with complementary inputs = 24V p-p AC bridge output. Not appropriate for a high current PMDC motor! \$\endgroup\$ – Bruce Abbott Aug 22 '16 at 15:56

your circuit seems fine , but it doesn't contain a current limiting protection . and you might be driving the motor directly without ramping the PWM . So my guess what is happening is that the motor is accelerating and decelerating quickly causing High voltage spikes on the 24v bus . by the way if your 24v is from a bench power supply then it can cause a disaster , it should be battery or batteries in parallel to power supply to absorb the regeneration energy .

Another aspect is the DC DC converter choice , 1W might not be enough and isolation is not needed since you are using a bootstrap driver . So use a 7812 instead it will work flawlessly.

So my proposed solution :

1. Use Battery for 24v supply

2. use a TVS on 24v bus to absorb the transients

3. Ramp the PWM every 1 ms 1% for example , to accelerate/decelerate slowly to prevent spikes from happening

4. Use a small 1A to 2A dc motor to test the system , check the signals with oscilloscope , if every thing works fine , install the big motor .

general note: NEVER put the oscilloscope ground pin on the Vs terminal when trying to measure the high side transistor gate . instead measure the High side gate signal with respect to ground ( it will be around 36v).


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