RESPOND TO TWO CLASSMATES POSTS FOR ELECTRONICS ENGINEERING COURSE

POST 1:

In a bedroom you could possibly have a variety of different types of switches, the most common one you’ll find is a single pole single throw switch. As my classmate Liviu has already mentioned when this switch is in the closed position (On) there are zero volts going across it. When this switch is in the open position (Off) there is 120 volts across it. The other types of switches you could possible have are a motion sensor switch or a dimmer and fan control switch if you have a ceiling fan. In the dimmer and fan control switches when they operate in the between positions of closed and open they regulate the amount of voltage that is being fed to either the light or the fan. Making the light dim and the fan either slow down or speed up. Enclosed are a couple of examples of this.

Figure 1. Simplified schematic of a leading-edge phase-cut dimmer (Including transient and surge suppression elements LS and CS)

Figure 2. Simplified schematic of a trailing-edge, phase-cut dimmer

http://www.ledjournal.com/main/blogs/leading-edge-vs-trailing-edge-dimmers/ (Links to an external site.)Links to an external site.

POST 2:

At work we use RIB relays which take a 24V AC or 10V DC signal from our control board and pass through a 120V or 277V signal to operate a piece of equipment depending on the configuration. This allows us to control higher voltage equipment with our control boards that only have the capability to output 24V power. The control voltage acts as a switch for the higher voltage.

http://www.prothermostats.com/product.php?product=…