Both magnet charger MC & MCa series are fully
microprocessor controlled with adjustable capacitor voltage from 50v to
maximum (in 1v step) with feedback via a digital display. The
microprocessor controls the charging and discharging of the machine
ensuring that the charging is managed in a way to reduce the initial
charge current that non-microprocessor systems may not have. The
microprocessor also performs fault monitoring for system protection.
Each magnet charger is fitted with an internal dump
resistor to discharge the main capacitors in power down or abort mode,
ensuring a safe environment for both operator and machine.
The MC & MCa series has incorporated as standard a
PLC control interface. This allows the unit to operate manually,
integrated into an automatic production line or used for data
collection. An optional RS232 interface provides even more
as each unit can be interfaced with a fluxmeter to measure field
density and offer additional quality control benefits.
The MC series (as defined by the energy output, in
joules, to the magnetising fixture i.e. MC4kJ) is based upon
electrolytic capacitor technology and is ideal for high production
rates and magnetising to saturation permanent magnets and permanent
Capacitors are normally configured for a maximum voltage
of 760 – 800 volts, but can be configured for 400v output.
Typical energy outputs for the above range span from 750J to 20kJ.
The MCa series is based on non-polarised capacitors
technology that allows high peak currents and shorter magnetising
pulses as often used in multipole magnetising of rare earth magnets.
Capacitor voltages of up to 3,000 volts are available in
the MCa range.
Typical range of energy outputs for the above series
span from 100J to 20kJ..
Principles of operation
In most applications the required current is too large
to be directly driven from the mains and/or the fixture’s
inductance/resistance is such that not enough current would flow to
produce the required magnetic field. A capacitor bank is,
charged to the required voltage level (up to 3,000 volts) and this
stored energy is then discharged by a thyristor into the fixture to
produce the required magnetic field.
In a magnetising operation a clamp or freewheel diode is
placed across the fixture to ensure no reverse energy charges the
capacitor bank negative. All the energy is dissipated into the
as a magnetisation pulse.
Ignitron outputs will be offered instead of
semiconductor devices if the peak current is exceedingly high and/or
the rise time of the pulse is very short.
Ignitrons may also be offered for machines where the
fixture is “unknown” or where fault conditions are expected that could
damage semiconductor output devices.
The MC series can easily be integrated with mechanical
Both MC and MCa series features an easy to use control
panel that includes:
Four Buttons Operation Control
Pulse (Green) – to initiate a magnetisation cycle
Abort (Red) – to abort the current sequence
Up and Down (Yellow) – allows the adjustment of
LCD display – shows the current voltage level, status
and error messages
Key switch – available as an option to lock the
PLC interface – allows integration with automated
RS232 interface – optional extra
Magnet charger energy will be selected to meet the
requirements of the application and will be dependent on the fixture
design. Typically, due to the high cost of energy storing
the higher the energy needed to satisfy the magnetising application the
higher the cost of the magnetiser.