The AC HotStick consists of a high sensitivity AC amplifier for the frequency range below 100 Hz. The special logarithmic amplifier is capable of receiving AC signals over a very wide amplitude range. Such signals, emanating from an unshielded, voltage-carrying surface, can be made audible and visable as a signal.
The warning signal (beeps and LED flashes) become more rapid as the AC HotStick approaches the source, making source location quick. In the presence of high tension wires the sensitivity can be reduced by selecting the Low sensitivity or the Front focused mode. The sensitive section of the AC HotStick is located in the red striped area. When used in the High or the Low sensitivity mode the unit will respond to signals from all sides (omni-directional sensitivity). When the Front Focused mode is selected the unit responds only to signals received from the front of the AC HotStick. This reduces the sensitivity and concentrates detection into a small frontal area, permitting pinpointing of the source and distinguishing between adjacent wires.
The detector will not respond to DC voltages from car batteries or from the third rail in light rail transit vehicles operating on DC.
The unit features a complete self-test circuit: Immediately after turning the unit on, a built-in, low frequency oscillator will operate for about 3 seconds simulating power line signals. Rapid beeping for about 3 seconds indicates proper operation of the unit.
A low voltage watchdog circuit monitors the battery power. If battery power is too low, the unit will make a constant warning beep, alerting the user to replace the batteries. The unit requires virtually no warm-up and is operational about 10 seconds after being turned on. In normal use with intermittent operation, a set of standard AA alkaline batteries will typically provide one year of service. If left on continuously the batteries will run down in about 300 hours. In order to assure operation and prevent battery leakage, the batteries should be changed annually.
After unscrewing the lanyard the batteries are accessible. Batteries should only be changed in a clean, dry atmosphere. The electronic circuitry is mounted on a printed circuit board housed in a sturdy, fully insulated plastic pipe. The set is splash-water proof. It has been designed for operation in potentially explosive atmospheres. Hermetically sealed switches and quality components provide reliable operation and long life even in severe environments.