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Electro Permanent Magnet

EPM688-5

New product

 

< Obsolete- replaced with EPM 688-V2.0 >

The EPM688-5 is an Electro Permanent Magnet, combining the advantages of electro and permanent magnets. This Device comes with integrated electronics that can be operated with 3.3 and 5V TTL signals and uses 5V Vcc. It can hold up to 8kg. 

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OpenGrab Electro Permananet Magnet

EPM688-5, EPM688-5-S, V1.0X, V1.2

General Description

The EPM688-5 and EPM688-5-S are Electro Permanent Magnets, combining the advantages of electro and permanent magnets. This Device comes with integrated electronics that can be operated with 3.3 and 5V TTL signals and uses 5V Vcc.

Applications

  • Robot arm work holding
  • Cargo lift for UAV's
  • Educational demonstration of magnetic properties

Features

  • 5V Vcc
  • 3.3 or 5V TTL signal
  • Minimal steady state power <1mW
  • Water resistant conformal coating
  • 330V shocks are possible when touching the unit (patent pending auto weakup feature)

Recommended Operational Conditions

Symbol Parameter Rating Units
Vcc min Power supply Voltage 5 V
Vcc min V1.2 Power supply Voltage min 3.3 V
Vcc max Power supply Voltage max 6 V
Imax Maximum Supply Current 1.5 A
Vsig low Maximum low signal Voltage 1? 2.2 V
Vsig high Minimum high signal Voltage 1? 2.8 V
Vsig max Maximum signal Voltage 5 V
Tmax Maximum Temperature 2? 50 deg C
Tcharge Charge time 3 s
Fmax Max holding force 80 N
Mass Mass 55 gram

1? Vsig is undefined between 2.2 and 2.8V. Operating the signals this area may cause premature turn off of the IGBT under high current conditions causing permanent damage. Oscillation on either the Vsig Vcc may cause rapid turn off and on of the IGBT. This can be avoided by using a clean power supply. http://www.nxp.com/documents/data_sheet/74HC_HCT32.pdf 4HC_HCT32.pdf] should be consulted. This is not a problem with V1.2 which will not suffer damage from noise.

2? Without electrolyte capacitor 80 deg C

Pin Functions

Gnd (Pin 1 and 6)

Ground pin

Vcc (Pin 2 and 5)

5V supply <100mV ripple

S_off (Pin 3)

Pulling this pin high (it has a 1 kohm pull down) causes the magnet to go in the off state if the capacitor is charged, the discharge will automatically stop in 300uS even if kept high. Holding this pin high for 3s charges the capacitor to full and is ready for the next cycle. The relative high self discharge rate of the capacitor should be taken into account, recommended time is <10s.

S_on (Pin 4)

Same as S_off

Gehäuse 1-6

Breakout of the 6 contact points for use for electrical contact. The 6 individual metal contacts on the bottom are broken out so one may solder a connector to the board. This is intended to be used with a recharge station.

Operation

The EPM688-5 is designed to hold securely a cargo of 1kg and switch on and off effectively with low power consumption. 800mA at 5V for 3S or 3.4J per cycle.

Under the capacitor discharge condition pull either S_on or S_off high >2.8V for 3 seconds and then low. The capacitor is fully charged and the device is ready to cycle. Pulling either S_on or S_off high causes the magnetic field to move either in the on or off state. Care should be taken that the S_on or S_off are set high for no less then 500uS otherwise IGBT turn off under high current condition can cause damage. Pulling S_on or S_off low after >500uS have expired causes the driver to charge the capacitor, automatically stopping once 330V is reached in about 3s.

Drawing