diykits.com.hk clock help

[nad]

Hello,

Can anyone help me??


I have a dikits.com.hk TCXO clock kit.
It's all populated and ready to go in but I have no 12vac in the CDp , it states you can use direct 5vdc, anyone know how I should wire it at to 5vdc??

Do I remove/jumper the rectifier and go directly?



Thanks

[nad]

Seems if it's not a CD63 nobody is interested?????

[amc184]

Originally Posted by nad

Seems if it's not a CD63 nobody is interested?????

Probably more likely because this is an obscure kit that isn't well supported.


Personally, I wouldn't connect 5VDC directly to it, as you'll lose any benefit the clock's power supply would have afforded you. How you'd connect is really depends on what voltages are available inside your CD player.

The power supply is designed to regulate about 16.5VDC (regulated 12VAC), so if your player has a 15VDC supply, that may suit. If you post the values of the two resistors connected to each LM317 regulator, I'll be able to tell you what range of voltages is suitable.

But to be honest, the best way to use the clock is with its own 12V transformer, like the designer intended. Add a small 240V to 12V transformer inside the case.

[nad]

I'm going to go the route Wu (diykits) intended.
The only problem I have is I'm new to electronics and I know I'll need a transformer, but which one is the question?

I've been looking for a 12v ac toroidal but see there are primary/secondary windings, how do you wire them for 12v ac out?

Can anyone help? I'll be purchasing it from farnell so if anyone can point me at a specific item on the site (item no??) then that would be great.


Thank you

[amc184]

Farnell product number 9530231 looks good. To wire this one up, you'd need to make the following connections:

Primaries:
Brown lead to Phase
Blue lead to Neutral
Connect violet and gray leads together

Secondaries:
Red lead to either of the 12VAC terminals on the PCB
Orange lead to the other 12VAC terminal on the PCB
Connect black and yellow leads together

Also, as with any mains electricity project, there are many rules to follow, such as:
- There must be a fuse in mains supply to the transformer. A fuse value of 100mA would be about right.
- If the CD player you are installing this into is double insulated, make sure your work is too.
- Make sure you don't form a shorted winding with the transformer.

[nad]

Originally Posted by amc184

Farnell product number 9530231 looks good. To wire this one up, you'd need to make the following connections:

Primaries:
Brown lead to Phase
Blue lead to Neutral
Connect violet and gray leads together

Secondaries:
Red lead to either of the 12VAC terminals on the PCB
Orange lead to the other 12VAC terminal on the PCB
Connect black and yellow leads together

Also, as with any mains electricity project, there are many rules to follow, such as:
- There must be a fuse in mains supply to the transformer. A fuse value of 100mA would be about right.
- If the CD player you are installing this into is double insulated, make sure your work is too.
- Make sure you don't form a shorted winding with the transformer.

Super, thank you for your time.

[amc184]

No problem.

If your new to electronics, it might be best to post some photos of your install before you apply power to it, so others can check that it looks alright.

Anton

[nad]

Originally Posted by amc184

No problem.

If your new to electronics, it might be best to post some photos of your install before you apply power to it, so others can check that it looks alright.

Anton

Great idea, thanks again.

Ant

[nad]

Originally Posted by amc184

- There must be a fuse in mains supply to the transformer. A fuse value of 100mA would be about right.
- If the CD player you are installing this into is double insulated, make sure your work is too.
- Make sure you don't form a shorted winding with the transformer.

-Do I not need a fuse before and after the transformer?

-Double insulated? I'm unsure of what you mean, sorry.

-Shorted winding? is that wired incorrectly?


Thanks

[amc184]

Okay, put the fuse in as per the attached diagram. A secondary fuse is not necessary.

There are two types of appliance, grounded and double insulated. With grounded appliances the chassis is connected to ground, and the power cord will have a ground pin (three pins total). Double insulated appliances are not grounded, and will only have a two pin power cord. They use two layers of insulation to ensure they remain safe.

If your CD player is double insulated, and a lot are, you need to put two layers of insulation on all the 240VAC cables and fittings you add to make sure the player will still be safe after you modify it.

A shorted winding is formed when you somehow make a conductive loop through the middle and completely around the toroid. The transformer will get very hot, then very broken. See diagram for example.