In essence, therefore, we have controlled 21 high-current network with a relatively small
dc voltage level and a rather inexpensive design. The only obvious flaw in the design is
the fact that the MOSFET will be on even when there is no intrusion. This can be reme-
died through the use of a more sophisticated design, but keep in mind that MOSFETs are
typically low-power-consumption devices, so the power loss, even over time, is not that
great.