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3.5.6 Motor brake connection
You might wish to wire a motor’s brake, via relays, to digital outputs on connector X3 (see section 3.3.1). This provides a way for the MicroFlex e100 to control the motor’s brake. A typical circuit is shown in Figure 10.
‘X3’ | User supply V+ |
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| DOUT0+ |
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11 |
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| The relays have normally open | |||
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| DOUT1+ |
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| contacts and are shown deactivated | |
13 |
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| (contacts open, brake engaged). | |||
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1DOUT0-
3 | DOUT1- | Relay 1 |
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| Relay 2 |
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| User supply GND | +24VDC | 0V |
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| Separate |
customer supplied 24VDC supply
Figure 10 - Motor brake control circuit
C
from motor brake
Dconnections
The inner shield surrounding the brake wires should be earthed/grounded at one point only.
This circuit uses the drive enable signal (configured using DRIVEENABLEOUTPUT to appear on DOUT0) in conjunction with DOUT1 (configured as the MOTORBRAKEOUTPUT). See the Mint help file for details. With this configuration, the following sequences can be used to control the brake.
To engage the brake:
HThe motor is brought to rest under normal control;
HRelay 2 is deactivated, causing the brake to engage;
HThe drive is disabled. This removes power from the motor and causes Relay 1 to be deactivated.
To disengage the brake:
HThe drive is enabled, activating Relay 1;
HPower is applied to the motor to hold position under normal control;
HRelay 2 is activated, causing the brake to be disengaged.
It may be necessary to include a small delay, after Relay 2 has been activated, before starting motion. This delay will allow time for the relay contacts to engage and the brake to release.
CAUTION: The 24VDC power supply used to power the brake must be a separate supply as shown in Figure 10. Do not use the supply that is powering the MicroFlex e100 digital outputs. The brake wires often carry noise that could cause erratic drive operation or damage. The brake contacts must never be wired directly to the digital outputs. The relay(s) should be fitted with a protective flyback diode, as shown. The separate 24VDC supply used for the motor brake may also be used to power the relay in the thermal switch circuit (section 3.5.5).
MN1942 |
