Fluorescent monomers are described and claimed which are synthesized by reacting a substituted or non-substituted naphthalic anhydride with an amine and with a moiety containing a polymerizable group. The safety device separately detects the forward and upward displacements of a combplate beam 12 with respect to a supporting beam 13 with a single safety switch actuated by a switch actuating member having first and second actuating portions to stop an operation of the passenger conveyor. Although the hardware designs have been fabricated in integrated circuit products with limited inputoutput pins, the techniques and systems enable the hardware designs within the integrated circuit products to be comprehensively analyzed, diagnosed, and debugged at the HDL level at speed. An integrator may integrate a transient current to generate an output signal, such as when the vehicle is subjected to an electrical charge.