The 4Q05100PS-420 Power Supply System consists of an AMI Model 420 Programmer, configured for 100 Ampere operation, and an AMI 4Q05100 DC Power Supply.

The Model 4Q05100PS-420 is a reliable, compact, and economical superconducting magnet 4-quadrant power supply system which provides up to ±100 amps at up to ±5 volts. (Refer to Graphs 1 and 2 for output power capability) The Model 4Q05100PS-420 is a hybrid linear/switched-mode design resulting in a compact, air cooled unit with very low output noise. The Model 4Q05100PS-420 system provides for finely-controlled charging of the inductive superconducting magnet load and eliminates magnet current oscillations.

The power supply is designed for remote voltage programming (i.e. voltage-to-voltage mode) to function as a slaved supply to the Model 420 Programmer.

The power supply is shipped preconfigured for "remote voltage commands output voltage" (i.e. voltage-to-voltage mode) to function as a slaved supply to the Model 420 Programmer.

The true, four-quadrant output capability of the Model 4Q05100PS-420 Power Supply System is ideal for the charge and discharge cycling of superconducting magnet loads. The versatile Model 420 Digital Programmer controls the Model 4Q05100 Power Supply and the combination has the ability to set either positive or negative current or voltage values. This true, four-quadrant operation significantly simplifies test procedures as well as system design by eliminating the need for external switching or operator intervention to reverse the direction of the current. The transition through zero current is smooth and continuous allowing the user to readily analyze samples at very small current increments about zero.

The Model 4Q05100PS-420 either transfers energy from the AC line to the magnet, or dissipates the energy internally as heat. Extensive output filtering and ripple cancellation circuitry was designed into the Model 4Q05100PS-420 to minimize the noise at the output.

Superior Resolution and Stability

The Model 420 Programmer utilizes 20-bit converters to translate signals between the analog and digital domains. Precision instrumentation techniques and potentiometer-free designs are employed throughout the instrument to ensure accurate signal translation for a wide range of conditions. The magnet current is sampled at a resolution of 0.2 mA. The encoder dial allows for fine adjustment at up to 15-digits resolution. All pause and hold functions are performed in the digital domain, which provides for excellent stability and low drift (<0.01%) of the programmed magnetic field.

Programmable Safety Features

The Model 420 Programmer is designed to allow the operator to program the system from the front panel, or remotely, with current and voltage limit parameters which will not be exceeded during operation of the system. Once set, should an operator inadvertently attempt to operate beyond the specified limits, the programmer will not accept the parameter and audibly beep. An appropriate error message is available via the remote interface. The Model 420 Programmer also automatically limits the charge rate of the magnet to the specified voltage limit.

The power supply system is also protected from any over-voltage, over-current, or over-temperature conditions.

Quench Detection

The Model 420 Programmer provides visual indication of a magnet quench and automatically commands the power supply output voltage to zero volts. (A manually-operated standby switch is also available on the front panel of the power supply.) The operator is prevented from initiating a recharge of the magnet until the Model 420 front panel quench detection switch is reset. A rear-panel input is also available to accept a user-generated quench indication if required.