[p-com wk 1] Old telephone switch


The lights were pretty dim but it does work

A couple days ago I found a funky and broken old telephone from the junk shelf on the floor. Ok, I thought, I need to use it somehow… a switch, perhaps?

I first made sure my breadboard prototype was working with a regular switch. I didn’t have a DC jack, so I wired the board through an Arduino Uno that connects to 9V DC power. 5V runs out from the 5V and GND output pins into the breadboard.

I wanted to test if the medal on the telephone would conduct, so I took down the light, resistor and switch from the previous setup, and ran the circuit through the telephone instead. Multimeter read about 0.019 V, so I assumed this meant the medal doesn’t conduct well? I also put the light and resistor back in to test it, and light only lit up occasionally. 

My friend and best cohort David Currie attempted to solder wires onto this weird metal material but failed, so I decided to use tin foil to both secure connection and better the conduction, wrapping in wires that connect both parts to the breadboard.

The result is promising:

After finishing the other labs, I went back to it and changed the circuit into parallel for two light bulbs (Rectangular green bulbs I, once again, found on the floor) 

These green bulbs weren’t nearly as bright, but I didn’t know if it was because the bulbs weren’t good, or that they needed more voltage, or the fact that current that ran across both were less because of the parallel setup. Mysteries be solved once I get more familiar with electricity and using the multimeter.

the final setup


Week two reflection

My lights are dim because I supplied 5V from the uno board, which already has built in regulators, and through the voltage regulator on the breadboard the voltage dropped even further.

To solve this, I could either use the Vin pin for Uno board output, run it through the voltage regulator, or I could just get rid of the voltage regulator and use the 5V from the Uno.

Mystery do be solved!

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