| Want a universal alarm? Engineer it yourself. The circuit in this article enables you to build a general-purpose alarm for a wide range of a...
All items tagged with Circuit and Alarm (15)
| Simply forgot to water it – and then you can wave goodbye to that expensive bonsai. A pity about all the work that went into it… But this dr...
| The alarm clock (radio) has seen two significant improvements since its invention. The first is the snooze button, and the second we present...
| For car alarms, emphasis should be put on hearing the audible alert and identifying it as belonging to your ‘wheels’. Unfortunately, modern...
| The author wanted a very cheap and simple alarm for some of his possessions, such as his electrically assisted bicycle. This alarm is based...
| The LM1830 fluid detector IC from National Semiconductor is designed to be able to detect the presence of fluids using a probe. This chip re...
| Here are two circuits that make it possible to add up to eight detectors to an existing alarm system without running a single cable. Each tr...
| It’s probably the worst nightmare for all PC owners: The fan has been quietly doing its job keeping the PC internals nice and cool but over...
| The alarm circuit uses infra-red light beams to bridge distances between 3 m and 5 m (10 ft to 16 ft), but if the transmit diode is give...
| These days, if you want to protect your home and valuables, you can't avoid installing a clever and reliable alarm system. The circuit...