SHK1 is an electrical pain stimulator for use in stress tasks or as UCS in conditioning experiments, etc. The maximum output limit switch prevents excessive shock. Current levels up to 5mA (RMS) are more than sufficient for normal pain stimulation tasks. The shocker was designed with reference to recommendations by Tursky and Watson. 60Hz, constant current AC stimulation is provided by an internal oscillator, independent of the AC power supply. Shock level and duration is controlled from the experiment control file; a number between 0 and 255 sets output level in the range chosen by the maximum limit switch. The device is medically isolated and has a safety cut-out which prevents the shock occurring unexpectedly after temporary power out.

SHK2 Somatosensory produces brief pulsed output suitable for use in direct nerve stimulation. Uses include eye blink, ERP, Nerve conduction, etc.

The SHK2 stimulator provides pulse current of up to 20mA, with a manual control to limit maximum level. As a safety feature, this control must be turned to the zero position after the unit is powered on, before the device will operate. This prevents unexpected currents occurring in the event of interruption of power, and also ensures operator consideration before using this high voltage electrical stimulation device.

Computer control of pulse duration is provided as 100 - 1023 micro Seconds in steps of 4 micro Second, and control of level is 0  max (level selected on manual conmtrol switch) in 256 steps.