Shopsmith Forums

It boggles my mind that those diodes were left flopping around in the middle of the hookup wiring, with the connections neither insulated and nor properly restrained. Was that definitely done by the manufacturer?

Could those exposed conductors simply have shorted to chassis ground? That certainly could explain blown diodes.

The diodes are actually acting like a crude rectifier creating a very dirty DC current like Bill points out above. I have to wonder why .....

BuckeyeDennis wrote:It boggles my mind that those diodes were left flopping around in the middle of the hookup wiring, with the connections neither insulated and nor properly restrained. Was that definitely done by the manufacturer?

Could those exposed conductors simply have shorted to chassis ground? That certainly could explain blown diodes.

I had to cut off the shrink tubing to get to them.

wa2crk wrote:Referring to pic "diode2" is the orange wire just below the blown diode burned?
In pic "diode1" there appears to be a scorch mark on the white wire left of the diode. Correct? Or not.Bill V

The orange wire has soot on it. There is a scorch mark on the white wire.

I don't understand any of the technical jargon. I don't know what a diode does. So, if I replace these are they directional (like a battery) or can I have them any direction?

What happens if I eliminate the diodes?

Let's start with some more basic info.

What is the brand and model of the toaster oven?

There may be a schematic or some repair info out there for this model, even recall or service bulletin info.

db5 wrote:

wa2crk wrote:Referring to pic "diode2" is the orange wire just below the blown diode burned?
In pic "diode1" there appears to be a scorch mark on the white wire left of the diode. Correct? Or not.Bill V

The orange wire has soot on it. There is a scorch mark on the white wire.

I don't understand any of the technical jargon. I don't know what a diode does. So, if I replace these are they directional (like a battery) or can I have them any direction?

What happens if I eliminate the diodes?

You betcha! They have a band on one end. It appears both were banded the same(the 'right' end).

Question is, why are they there/what do they do? They make no sense to me at this point.

It is difficult to see where the wires they connect to go.

I understand the timer switch/bell.

I understand the temperature 'control'.

I be curious what the 'modes' are.

JPG et al
The diodes only conduct on one half of the AC cycle. They are connected in parallel so that the current will divide and the load is split between the two diodes. If one diode were to open then all of the current would have to go through one remaining diode most likely over loading it. Everything in the toaster looks to be clean.
I have had lighting fixtures that had a high and low function and all that was done was to put a diode in the AC line when the low light function was selected effectively applying only half voltage to the bulb (incandescent of course). If the diodes are in the heater circuit they would only conduct on one half of the AC cycle. It would actually work but the elements would take longer to heat up but they would get hot. The diodes being in parallel would both conduct on the same half cycle but the current would divide between the two of them.
Bill V

wa2crk wrote:JPG et al
The diodes only conduct on one half of the AC cycle. They are connected in parallel so that the current will divide and the load is split between the two diodes. If one diode were to open then all of the current would have to go through one remaining diode most likely over loading it. Everything in the toaster looks to be clean.
I have had lighting fixtures that had a high and low function and all that was done was to put a diode in the AC line when the low light function was selected effectively applying only half voltage to the bulb (incandescent of course). If the diodes are in the heater circuit they would only conduct on one half of the AC cycle. It would actually work but the elements would take longer to heat up but they would get hot. The diodes being in parallel would both conduct on the same half cycle but the current would divide between the two of them.
Bill V

Outstanding Bill!
That seems very plausible. If there is two settings on temperature control, I think you could prove Bill's theory to be correct. I couldn't for the life of me figure out why they needed a rectifier on a heating element, but Bill's idea is right on and would explain it.

As always, JMHO

I take issue with paralleling diodes in an attempt to 'split the current'. No way will it divide 'equally' with over a hundred volts applied to the circuit. Now if each diode only 'fed' one element 'each' then it would make sense.

I cannot tell if the two elements were connected in parallel or series.

A reason for my 'mode' question.

Yep a maker/model/schematic would be quite helpful here.(or hands on )

The make is Euro-Pro Model T0242RW. I couldn't find a schematic online. Two pictures that should help.

In the first the AC line in goes to the diodes which are parallel. Note that one side splits off to the bottom heating element on the far left and also is connected to the function control. That control changes it from bake, broil, rotisserie and toast. the other diode also connects to the function control and the top heating element just out of sight in the lower right.

The white wire with soot on it was tied with a zip tie just above the diode that self destructed.

The second picture is of the controls from the front. Left is the Off/timer control, middle the function control and on the right the temperature control.