Hello all and greetings. I have scoured the internet for the answer to this question, but to no avail.
I am building a cheap 5e3 kit and am making good progress. However, there is one point I am stumped on. On the 5e3 transformer, you usually have two 5v wires for the 5y3 rectifier (pin 2 and pin 8 ). 
With my transformer, I have two wires, but one is 0v (center tap?) and one is 5v. 
My questions:
1. Do I put the 0v wire on pin 2 and the 5v wire on pin 8?
2. Do I ground the 0v wire and jump the white 5v wire between pin 2 and pin 8?
Thank you in advance! I am scratching my head on this one!
			
			
									
									
						5e3 Transformer Question. Please help!
Moderators: pompeiisneaks, Colossal
- 
				Stovemananon
 - Posts: 27
 - Joined: Sat Apr 09, 2022 12:51 am
 - Location: Greenville SC
 
- martin manning
 - Posts: 14308
 - Joined: Sun Jul 06, 2008 12:43 am
 - Location: 39°06' N 84°30' W
 
        
                                            1 others liked this
            
		Re: 5e3 Transformer Question. Please help!
Answered in the other thread where you asked about this. That winding has both 5V and 6.3V taps for the rectifier filament. just use the 0V and the 5V. The leads are described that way on the attached label, no?
			
			
									
									
						- pompeiisneaks
 - Site Admin
 - Posts: 4244
 - Joined: Sat Jan 14, 2017 4:36 pm
 - Location: Washington State, USA
 - Contact:
 
        
                                            1 others liked this
            
		Re: 5e3 Transformer Question. Please help!
If your question is more of 'does 0v or 5v go to pin2?' then that technically doesn't matter, no matter which direction the AC current flows across the filament, the plates will attract the electrons and they'll convert it to DC. 
~Phil
			
			
									
									~Phil
tUber Nerd!
						- 
				Stovemananon
 - Posts: 27
 - Joined: Sat Apr 09, 2022 12:51 am
 - Location: Greenville SC
 
Re: 5e3 Transformer Question. Please help!
Thanks to you both! 
So I am safe to assume that the 0v wire does not need to be grounded as a center tap and can be used on Pin 2 or 8? (with the 5v wire being on either as well)
Thank you! This brings me tremendous relief.
			
			
									
									
						So I am safe to assume that the 0v wire does not need to be grounded as a center tap and can be used on Pin 2 or 8? (with the 5v wire being on either as well)
Thank you! This brings me tremendous relief.
- 
				Stovemananon
 - Posts: 27
 - Joined: Sat Apr 09, 2022 12:51 am
 - Location: Greenville SC
 
Re: 5e3 Transformer Question. Please help!
Yes sir it is labeled as such. However, upon reviewing other kits, I see they have 2 yellow wires that have 5v between the two (rather than a 0v and a 5v wire separately). It was confusing me.martin manning wrote: ↑Sun Apr 10, 2022 3:18 pm Answered in the other thread where you asked about this. That winding has both 5V and 6.3V taps for the rectifier filament. just use the 0V and the 5V. The leads are described that way on the attached label, no?
- martin manning
 - Posts: 14308
 - Joined: Sun Jul 06, 2008 12:43 am
 - Location: 39°06' N 84°30' W
 
        
                                            2 others liked this
            
		Re: 5e3 Transformer Question. Please help!
Two wires with 5 VAC between the two could just as well be labeled individually as 0V and 5V.Stovemananon wrote: ↑Sun Apr 10, 2022 3:32 pmupon reviewing other kits, I see they have 2 yellow wires that have 5v between the two (rather than a 0v and a 5v wire separately). It was confusing me.
- pompeiisneaks
 - Site Admin
 - Posts: 4244
 - Joined: Sat Jan 14, 2017 4:36 pm
 - Location: Washington State, USA
 - Contact:
 
        
                                            1 others liked this
            
		Re: 5e3 Transformer Question. Please help!
Correct. A center tap is only used for one of two reasons, for heaters on a 6.3 volt heater supply, or if you've got a setup where you need the 5V Full Wave Bridge Rectified, which needs a center tap. technically speaking CT on a 6.3 volt heater winding is 3.2 - 0 - 3.2 i.e. it's 3.2V per leg of the transformer and 6.3 between the two leads, ignoring center tap.Stovemananon wrote: ↑Sun Apr 10, 2022 3:30 pm Thanks to you both!
So I am safe to assume that the 0v wire does not need to be grounded as a center tap and can be used on Pin 2 or 8? (with the 5v wire being on either as well)
Thank you! This brings me tremendous relief.
Your rectifier needs 5V to do it's job so you need both 0V and 5V on pins either 2 or 8. You can't wire them 'backwards' but both need to be on those two socket lugs.
~Phil
tUber Nerd!