Darth Vader Toaster

[killivolt]

I'm helping a friend with this and I don't understand the circuit. It won't stay down, it has an Electro-magnet to hold and then release.


I have no voltage on the 8050 vcc to gnd. I suspect the zener, based on what I've seen on the net. This looks as if it's all ac, my volt meter on gnd and vcc I have .47vac


**broken link removed**


Edit: Oh, and this is the 110vac version not 220vac

 

[Nigel Goodwin]

This looks as if it's all ac, my volt meter on gnd and vcc I have .47vac

It's almost all DC - the only AC is to the right of the dotted line.

Check across C1, there should be about 4V DC - if there's zero volts, then check on ohms, see if it's got a short across it (probably the zener short).

 

[killivolt]

Just got back. Tested no voltage, I pulled it from the circuit and no short with Diode test. Do you think it's leaky?

 

[killivolt]

I just replaced the zener still no voltage across C1. All caps ESR are good.

 

[Nigel Goodwin]

Just got back. Tested no voltage, I pulled it from the circuit and no short with Diode test. Do you think it's leaky?

Check R8, R9, R10 - are those the elements?.

Any of those would completely lose you power.

 

[killivolt]

On the circuit board I have locations marked R8,R9,R10 but, only R10 is there. So, I would guess that R8,R9 are not needed in the 110 version. R10 and R15 are on the control circuit board. The heating elements are heating if you just hold down the lever.

Edit: If I hold it down it only heats the inside element with the image of Darth Vader. So, it wouldn't toast the other side of the bread. I think I may have a bad element or some sort of thermistor is bad that was replace by R8 and R9.

 

[Nigel Goodwin]

Well it's powered from a crude potential divider, check the AC voltage across R15.

You might also check that the rectifier diode D2 isn't short?.

 

[killivolt]

Got it, there was a broken Tig weld on a jumper to the other heating element.

Thanks for the help.

kv

 

[Mickster]

Less than 3 hours from Oooh?, to Aaaah!

Great to be a part of this fine community.

 

[JimB]

May the Schwartz be with you, Dark Helmet!

JimB

 

[KeepItSimpleStupid]

What's the source of Vcc?

Other than that, cool design, but I've often wondered how they reset timing from Reheat, frozen & bagel and what happens when you twiddle the dark setting? e.g. Wait 30 s and then twiddle the dark setting What actually happens software wise?

 

[killivolt]

Ok, I made a mistake. I thought that the 4148 was a Zener. It's a signal Diode and is actually used in the decoupler of the holding coil, D3 which is not marked on the schematic is not on the circuit board either along with R8 and R9 not used in the 110v version.

KeepItSimpleStupid, I will get the voltage off when I make the connection. I'm having trouble finding someone with a small enough spot welder. I'll probably just pinch it with a screw assembly or something.

kv

 

[KeepItSimpleStupid]

Can you charge a big cap. I once had access to one of these small spot welders. The crazy thing used tubes of all things to charge the bank of capacitors.

Make sure you try a test weld first.

Know any orthodontists? They have them to weld braces. They are also used to make thermocouples. That's what we used them for.

The schematic didn't show an obvious source for Vcc. Meaning, I think there is a missing wire in the schematic.

 

[killivolt]

The schematic didn't show an obvious source for Vcc. Meaning, I think there is a missing wire in the schematic.

I wouldn't doubt it. I was having trouble too! I thought this was sort of strange. That's what you get pulling stuff of the net. The minute I saw the Cancel, Reheat and Defrost I new I was close.

kv

 

[KeepItSimpleStupid]

The lack of a Vcc source prevents blatant counterfeiting.

The toaster's real though. It's fabulous for grilling frozen hot dogs. 2X on Max, Frozen & Bagel and they come out yummy!

Pic of the toaster from the kitchen.

 

[ben7]

The lack of a Vcc source prevents blatant counterfeiting.

The toaster's real though. It's fabulous for grilling frozen hot dogs. 2X on Max, Frozen & Bagel and they come out yummy!

Pic of the toaster from the kitchen.

lol have you ever used resistor voltage dividers? cause the element and an extra resistor act as a voltage divider to provide the circuits with maybe 4.5-10 volts, and then the 240ohm resistor and zener and cap act as a voltage regulator.

VCC--R1--TP1--R2--GND

two resistors in series connected to a DC voltage source as shown above. lets say VCC is 10volts. the resistors R1 and R2 will split the voltage to about half the supply voltage-which is 5V-at TP1, ONLY if they are the same resistance. However you can change the voltage at TP1 by decreasing/increasing resistance of R1 and/or R2. However If you were to power a circuit with it, the more current the load draws, the more voltage drop there is. And of course, and the resistor divider is inefficient too as extra current runs from VCC to GND through the resistors.

-Ben

 

[killivolt]

Making a mini spot welder

Ok, I can't find anyone with a small enough spot welder. So, I'm going to attempt building a small one and for just one connection.

I saw someone say maybe you could use 2 12v batteries or maybe a Capacitive one using a bank of camera flash charging units. They are saying you can pick them up for nothing.

I don't want to go to the trouble of cutting up a microwave transformer and going to far with it. Just another thing I don't have room for in my shop.

I just need a one shot.

kv

Edit: Oh, the problem I have is that the jumper wire going from one element to the other has come off. Now I have to re-spot weld it to make a good connection.

 

[ben7]

I saw someone say maybe you could use 2 12v batteries or maybe a Capacitive one using a bank of camera flash charging units. They are saying you can pick them up for nothing.

NOOOOO don't use 12v batteries, when they get short-circuited they give off hydrogen, and using them as a welder will make a big explosion!

-Ben

 

[killivolt]

NOOOOO don't use 12v batteries, when they get short-circuited they give off hydrogen, and using them as a welder will make a big explosion!

-Ben

Any thoughts about using a bank of Camera Flash Charger's for disposable camera's ?

Edit: Maybe I will just use the Microwave Transformer and cut out the secondary and replace it with a heavy double rap of some thick cable and see what that will do. It's really small stuff.

 

[ben7]

Any thoughts about using a bank of Camera Flash Charger's for disposable camera's ?

Edit: Maybe I will just use the Microwave Transformer and cut out the secondary and replace it with a heavy double rap of some thick cable and see what that will do. It's really small stuff.

killivolt,

Sorry I took long to respond, but yeah you can make a welder with a MOT (Microwave Oven Transformer) or a bunch of capacitors from camera flash units. You can get those cheap disposable ones from any store that processes the film for them, they then throw out the cameras with electronics, and batteries after processing the film. what a waste

Make sure that if you use camera flash caps that they are all connected in parallel, and use a decent size wire to connect them together. Using the thick wire makes the resistance of the path of discharge much less, so more current will be transferred to the weld joint in a smaller amount of time, and with much less losses. You will probably need like 2000uF of flash capacitors to make a decent small scale spot welder. The good thing with flash capacitors is that they have a low internal resistance for quick pulse discharging You can use one or two charging circuits, they will just take much longer to charge the caps though.

If you use a MOT be careful not to overheat the primary and/or secondary, cause some MOTs can draw up to 30A at 120v with a shorted secondary. You will need to use VERY THICK wire for the secondary, and say 6-10 turns should be enough for the secondary. To help limit the total current the MOT draws make sure to leave the shunts installed on the transformer! If you have trouble with the MOT tripping your breakers, wire the MOT in series with a 500W or 1000W heating element, depending on the rated wattage of the MOT

-Ben

BTW gonna get my first MOT to play with in two days
don't worry I will be VERY careful