Introducing NEW - PWRguard PLUS

Article from the West Mountain Radio November 2011 Newsletter


West Mountain Radio is excited to announce its latest generation automatic safety switch, PWRguard Plus. Like its predecessor, PWRguard Plus protects your radio, power supply and battery by turning off whenever an undervoltage or overvoltage condition is detected, then automatically turns the power back on when the voltage is within a safe operating window. PWRguard Plus extends this functionality to better meet the needs of amateur radio operators worldwide:

• Lockout triggering through external sense input
• Factory programming of custom trip limits
• 40 amp maximum current while transmitting, 30 amp continuous duty
• Soft turn-on / turn-off solid state switch

PWRguard Plus can cut off power to a rig by sensing an external relay contact or switch closure, or a low voltage (3 to 5VDC) signal. For example, this could be used to implement a safety keyed lockout switch that would prevent a rig from being accidently turned on while the antenna is being serviced. In the UPS shown below, a normally open keylock switch conected to the PWRguard Plus is used to cut power off to the rig when the switch is closed. The low-cost keylock switch is available from Digikey, part number EG2625-ND.

UPS with PWRGuard Plus and Keyed Safety Lockout Switch


PWRguard Plus will automatically turn the power off when its input voltage exceeds 15 volts or drops below 11.5 volts. Momentary dips below 11.5 volts are tolerated to prevent false tripping. Custom trip limits now can be programmed to suit a customer's specific needs; for example to accomodate different battery chemistries, cabling voltage drops, or a rig's input power requirements.

PWRguard Plus will deliver 30 amps continuously but can handle up to 40 amps during periods when a rig is transmitting. It uses a solid state switch to control the voltage output, eliminating the contact bounce inherently found in relay controlled outputs. The switch turn-on and turn-off is also slew rate limited, softening the transition to slightly reduce in-rush current.

In addition to the previously provided indicator LEDs, an audible alarm has been added to notify the user that PWRguard Plus has turned the power off. The alarm sounds off once per minute unless the user has disabled it.

To learn more about PWRguard Plus, go to http://www.westmountainradio.com/PGPNL