Salvaging wires and hacking a 240V to 9V transformer from an adapter

The 7th graders from Udavi School took a project on creating a PA system. To start of we required a lot of wires so the quest for salvaging wires began. The students picked every wire possible in STEMLAND that was not being used, we had a long Ethernet cable that was damaged and removed the outer casing and rolled up the inner wires. Once the required amount of wires were acquired we needed a power supply, a broken adapter that was found among the damaged equipment’s came into good use. We opened the case and took the transformer.

Then the primary and secondary winding s were checked for connectivity using a multi-meter.

Next the transformer was hooked up to a plug and carefully soldered and covered using heat shrink cables for maximum protection from the input voltage, thus it was ready to be tested.

The output of the transformer was connected to the oscilloscope, but only showed 2V to 3V. But when tested with a multi meter it showed 8.5V the expected voltage. This was a little confusing. In the end  by accident after removing the power we touched the transformer it was really hot. the adapter that the transformer was salvaged must have had burnt the core of the transformer, a while back. Then the hunt for a new transformer began.