FLOATING SUPPLY
HSP power supplies are equipped with an internal auxiliary supply which provides 5V at loads up to 100mA. It is derived from the internal cooling fan supply and is, therefore, present whenever the source power is within specification and the internal bias supply is operating, regardless of the status of the output regulator. This supply is SELV and is isolated from the output power lines as well, permitting the user to employ this supply to power circuits which do not share the same ground return as the output; in fact, this supply provides interface power for the remote inhibit control signals. Typical applications include single-circuit control of several HSP power supplies operating at various potentials and polarities with respect to the controller. The output is protected against overload, and is diode isolated to permit paralleling with the auxiliary outputs of other HSP units (regardless of model) for additional load capacity or redundancy. This output is available at I/O connector pins 26 and 25 (5VAUX and AUXRTN, respectively).
Module Current Monitor
HSP power supplies provide a 0-5.5V analog signal named IMON, accessed via I/O connector pin 32, which duplicates the signal level of the load sharing feedback signal (ISHARE) generated by each HSP. This permits the user to determine the load being provided by each module within a parallel or redundant power system configuration. The IMON signal is current-limited and isolated from the ISHARE signal, so that it cannot affect the load share function if shorted. The voltage level of this signal is generated with respect to the negative sense return (pin 19).
