Paul Hynes SR7 and SR4 Build Calendar Thread

[Lebouwsky]

I agree with @austinpop
 

The specified voltage (V) rating of a fuse is where it is garantied to function properly. When a higher voltage goes through the same fuse it might blow without causing an actual danger for the divice. 
 

Fuses are designed to respond to current (A) and blow when current is to high in order to protect the device.

 

So in your case you should use a 230v 1.6A slow blow fuse. 

[ejn1]

2 hours ago, auricgoldfinger said:

 

I believe the fuse value for 220v would be half of 1.6A, but get confirmation from someone else with more technical knowledge than me.

i cant recall what Paul had installed in my SR5 when in the UK, but when I moved back to the US and switched to 110v, he recommended i move to the following fuse (his words):

 

" 3.15A time delay for 110vac mains"...  

 

So by your logic above, i would assume you already have the amp rating at 1.6A for 220v?

[One and a half]

17 hours ago, IRS2092 said:

Check this

https://micro-audio.com/store/product/micra-p5/

Already underway.  there's no heatsink, how to cool the regulator,  hmm. Good price though and they are not hiding the heritage, whether it works is another story , but it's priced OK. 

[IRS2092]

4 hours ago, One and a half said:

Already underway.  there's no heatsink, how to cool the regulator,  hmm. Good price though and they are not hiding the heritage, whether it works is another story , but it's priced OK. 

Its pretty easy, just bolt it to a bigger heat sink if needed mine worked out without big heat sink.

 

You wont regret that purchase, it will work out just perfect and you will find out.

 

Yes, the price point is so cheap!

[AngeloVRA]

20 hours ago, Lebouwsky said:

The specified voltage (V) rating of a fuse is where it is garantied to function properly. When a higher voltage goes through the same fuse it might blow without causing an actual danger for the divice. 
 

Hi @sakso136

 

Adding to the above, the voltage rating of a fuse mainly refers to the fuse’s ability to prevent internal arcing across the melted fuse link after it blows. For example if a 220v volt fuse is used in a circuit with 600v, after the fuse blows due to an overcurrent condition, the current may still arc across the melted fuse link and conduct electricity. For the SR5, just use 230v fuse whether it’s used for 110v or 230v 
 

[sakso136]

21 hours ago, Lebouwsky said:

I agree with @austinpop
 

The specified voltage (V) rating of a fuse is where it is garantied to function properly. When a higher voltage goes through the same fuse it might blow without causing an actual danger for the divice. 
 

Fuses are designed to respond to current (A) and blow when current is to high in order to protect the device.

 

So in your case you should use a 230v 1.6A slow blow fuse. 

Thks

[sakso136]

22 hours ago, austinpop said:

 

These are generic comments, I don't have an SR5T. But assuming your unit has a slider or a knob to select between 110/120v and 220/240v, this is the first thing to get right. I believe that sets the transformer to the right winding ratio. It sound like you left it at 110v, then applied 220v, and your fuse has blown. Hopefully — hopefully — the fuse blowing protected your unit from any damage. The best way to test it is:

• Set the voltage slider or knob to 220/240v
• Replace the fuse with a generic one of the same rating: 1.6A, slow blow. Plenty of time for boutique fuses later. Right now, you want to see if the unit is working
• Turn it on, and test the voltages out of the 2 rails with the DC volts function of a multimeter
• If you get the correct voltage on both rails, breathe a sigh of relief that you dodged a bullet
• If it's inoperative, and the fuse is still OK, then the unit needs repair.

Good luck.

 

Wise words!

on my way industrial 2A 230v slow blow fuse, tommorow i should receive it,1.6a not available here i need to wait end of the month for it.

my friend told me 2A should be ok

[AngeloVRA]

Hi @sakso136

 

Here are some calculations for you:

if your SR5 has 1 rail, it probably has an 80va transformer which will draw 80va//220v = 0.4A. You can unscrew the front panel, take it off and you will see the transformer label..

 

 

However when you switch it on, for the first few seconds there will be an inrush current. The SR5 does not have a soft start module unlike the SR7T/DR7T. Hence it is recommended that you fuse 300% of steady current. That will be 0.4A x 3 = 1.2A…. Then you round up to the nearest fuse, which is 1.6A (2.0A is still okay)

 

if your SR5 has 2 rails, then it will most probably have 150va transformer (the maximum size of transformer that would fit the SR5 chassis) which will draw 150va/220v = 0.70 amp…. Fuse it at 0.70A x 3 = 2.1A to take care of inrush current and avoid nuisance fuse breakage. 
 

Hope that helps. 

[flkin]

I would follow what @AngeloVRA  says - he's a master of Paul Hynes devices... 😄

[sig8]

Is Paul Hynes still active, making power supplies? I sent an email ir bounced back. I have bought few power supplies from him in the past.

[BigAlMc]

6 hours ago, sig8 said:

Is Paul Hynes still active, making power supplies? I sent an email ir bounced back. I have bought few power supplies from him in the past.

 

Nope. Paul Hynes has gone bust or ceased trading for well over a year now, perhaps two years or more.

[Windows X]

Hi. Just heard news about Paul Hynes closing business.  Can't believe it's 2 years now. To be honest, I have a hunch that Covid would great affect his business as it did on my Nikola linear power supply design too.

 

The production cost increased a lot during Covid times. several parts shortage from main suppliers and parts increased a lot. If customers already paid for their orders months or even a year ahead of schedule, production cost for their units will likely go higher.

 

I also adjusted the price due to changes on production cost that both technician and I are okay with. As long as people involved in production are okay with it, business can continue as long as it meets demand on market.

 

Regards,

Keetakawee