Member
Joined 2002
I need help with the x-bosoz 
mine is fried and another psu down the drain I was getting 20V - and 35V positive. what have i done wrong ? im looking at the xcel sheet that they have put up on there site and its part for part.
Pic's can be posted if needed. R4 on the other boards is now toast
mine is fried and another psu down the drain I was getting 20V - and 35V positive. what have i done wrong ? im looking at the xcel sheet that they have put up on there site and its part for part.Pic's can be posted if needed. R4 on the other boards is now toast
Member
Joined 2002
When I was getting the low voltage on the positive side, it turned out to be my mistake in hooking up the transformer. One of the primary connections was not tight, so it was overloading and dropping below the required voltage for the regulator to have any effect. I would suggest carefully (these are dangerous volatges.) checking voltages upstream of the zener/FET to make sure you are not starving the regulator.
Only other thing I can think of is making sure the 610 and 9610 are not switched.
Craig
Only other thing I can think of is making sure the 610 and 9610 are not switched.
Craig
Member
Joined 2002
Member
Joined 2002
Member
Joined 2002
The transformer is connected like this..
Positive rail.
white/oranged shorted to gether to get voltage of 60V it is a 2 x 30V
Yellow goes to AC+1
Black goes to AC+2
Negitive rail
The other transformer 2 x 12V orange/white shorted again to get 24V
Yellow goes to AC-1
Black Goes to AC-2
I can post a picture tonight when i get home I hope i didn't ruen any thing.
Positive rail.
white/oranged shorted to gether to get voltage of 60V it is a 2 x 30V
Yellow goes to AC+1
Black goes to AC+2
Negitive rail
The other transformer 2 x 12V orange/white shorted again to get 24V
Yellow goes to AC-1
Black Goes to AC-2
I can post a picture tonight when i get home
I hope i didn't ruen any thing.
Member
Joined 2002
Member
Joined 2002
Jason check that your FET is ok by measuring the resistance between the pins. With the power off if you have a short (observer correct polarity with your ohmeter) between the Drain and the Source pins you have a bad FET for sure.
It only takes a momentary short of the outputs to kill these FETs. I killed my IRF610 when measuring voltage output early on in my experimenting.
It only takes a momentary short of the outputs to kill these FETs. I killed my IRF610 when measuring voltage output early on in my experimenting.
Can get it to work
I have bridged in - and in grd and done the same with out. But now insteed of a weak sound in the speaksers idont get any signal at all.
It is the same on both the bords.
Do anyone have any ides what canbe wrong. The voltage from the power supply is about +70 and -22 v.
I am very greatful for any help.
I have bridged in - and in grd and done the same with out. But now insteed of a weak sound in the speaksers idont get any signal at all.
It is the same on both the bords.
Do anyone have any ides what canbe wrong. The voltage from the power supply is about +70 and -22 v.
I am very greatful for any help.
Jason,
A general practice I use with every project (one I suggest for everybody) is to always test projects in the smallest convenient portions before assembling a project as a whole. I learned this through the many experiences of building projects to completion before performing any testing, only to find it not working properly and needing to disassemble it down to smaller portions in order to find the source of the problem. In fact, I don't think I have ever had a project ever be perfect on the first attempt. Now when I buy parts for a project, I also buy parts to create dummy loads and circuits so I can test protions of circuits as I build. Saves me a lot of frustration.
In your specific case, here's what I suggest. Lets first find out if the problem exists in the power supply or the pre circuit. Disconnect the pre circuit from the power supply. Find a couple of 25k or larger resistors (1/4W rated). Connect one between the power supply positive rail output and ground. Connect the other between the negative supply rail and ground. Turn on the powersupply and measure the AC voltages before the bridge rectifier diodes. Next, measure the DC voltages of the unregulated rails immediately after the bridge rectifier diodes. Then measure the DC voltages of the regulated rails at the power supply output. Lastly measure the DC voltage across the Zener stacks of the positive and negative sides, and also measure the voltages across the resistors that bias the zener stacks (R3 and R5?). Report these back here, and we will have a pretty good idea if the power supply is working correctly, and where the problem might exist. This experiment will run the power supply at between 1 and 3 mA, which will be a very easy load for the power supply, and ensures that we don't overload it. If you have a variac, you can do more or less the same thing, but with even less risk as you can start with supplying only 20 or 30V AC instead of hitting with an instantaneous 120V.
We'll get you up and running.
Cheers, Terry
A general practice I use with every project (one I suggest for everybody) is to always test projects in the smallest convenient portions before assembling a project as a whole. I learned this through the many experiences of building projects to completion before performing any testing, only to find it not working properly and needing to disassemble it down to smaller portions in order to find the source of the problem. In fact, I don't think I have ever had a project ever be perfect on the first attempt. Now when I buy parts for a project, I also buy parts to create dummy loads and circuits so I can test protions of circuits as I build. Saves me a lot of frustration.
In your specific case, here's what I suggest. Lets first find out if the problem exists in the power supply or the pre circuit. Disconnect the pre circuit from the power supply. Find a couple of 25k or larger resistors (1/4W rated). Connect one between the power supply positive rail output and ground. Connect the other between the negative supply rail and ground. Turn on the powersupply and measure the AC voltages before the bridge rectifier diodes. Next, measure the DC voltages of the unregulated rails immediately after the bridge rectifier diodes. Then measure the DC voltages of the regulated rails at the power supply output. Lastly measure the DC voltage across the Zener stacks of the positive and negative sides, and also measure the voltages across the resistors that bias the zener stacks (R3 and R5?). Report these back here, and we will have a pretty good idea if the power supply is working correctly, and where the problem might exist. This experiment will run the power supply at between 1 and 3 mA, which will be a very easy load for the power supply, and ensures that we don't overload it. If you have a variac, you can do more or less the same thing, but with even less risk as you can start with supplying only 20 or 30V AC instead of hitting with an instantaneous 120V.
We'll get you up and running.
Cheers, Terry
Member
Joined 2002