NL201 – Spike Trigger

A gated amplitude discriminator for nerve spikes and other events which produces separate output pulse trains for spikes which (i) cross the upper voltage threshold, (ii) cross the lower voltage threshold or (iii) cross the lower but not the upper threshold. Two potentiometers control window height and aperture settings. This module is often used in conjunction with the NL104A AC preamplifier. The amplified signal from the NL104A is fed into the NL201 which can detect extracellular spikes and send an output pulse corresponding to each action potential.

NL601 – Pulse Integrator

The NL601 has a digital counter which produces an analogue output proportional to the count. A pulse at the input socket increments the counter towards a full scale count of 255, 2550 or 25500 which is selectable by the front panel scale switch. The counter will continue to increment on input pulses until the unit is reset. This can be done manually (with the on, off/reset switch) or by applying a pulse to the reset socket. Alternatively, with the unit set to internal-reset, when the counter reaches full scale the unit will automatically reset.