Softstart and PWM circuit was tested successfully ! the value of the 2.7K resistor behind the 8.2K must be change to 180 Ohm for 80KHz output.
please check the new version of transformer secondary and tell me about it. also help me for choosing correct wire diameter for 24v lines. Thanks MicrosiMI advice you to make additional winding fro AUX supply.![]()
"DIYSMPS"DANGER ! HV AROUND , DEATH is PERMANENT
Very Good!
Transformer is OK, and its better to do it that way.
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Rigol 1102E and Hameg X100 Probe were arrived.
pwm circuit also tested with the scope and pictures of test is available on attachments.
next step : working on 16v 0.5A smps and over current protection , also testing gate driver with 2110.
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i have a question , if the 0.10mm wire not available , can i use the 0.2mm wire ?
for example : for primary using of 6x0.20mm and for secondary using of 9x0.2mm.
how can i calculate it ?
"DIYSMPS"DANGER ! HV AROUND , DEATH is PERMANENT
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thanksScope looks good!
yes , but it's under development.Whats that SMPS 16V 0.5A ? are you going to use small SMPS for AUX supply?
thanksfor the wires, you can use 8 x 0.2mm for both primary and secondary.
Dont forget to twist wires all over each others, firmly
yes , sure ! what do you do for measurements of smpses ? don't connect the gnd of scope ? or using the isolating transformer ?Dont forget ISOLATION TRANSFORMER
"DIYSMPS"DANGER ! HV AROUND , DEATH is PERMANENT
actually i'm going to make a smps instead of 18v-0.25 PCB Transformer , not for aux (+/- 24v).are you going to use small SMPS for AUX supply?
"DIYSMPS"DANGER ! HV AROUND , DEATH is PERMANENT
I advice you to use Isolation transformer.
I use 220VAC Primary to 110VAC secondary. Transformer to power my oscilloscope.
Transformer I am using is normal transformer being used in old amplifier! and it does the job perfectly!
While My oscilloscope operates from 100VAC to 220VAC, I have no problems!
So try locating something close, around 300W 110VAC, if your oscilloscope operates at 110VAC
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Thanks MicrosiM , so you use the isolation transformer for power the scope.
when i search on the internet , i have seen the rigol 1102 or many digital scopes , using the smps for powering the circuits and that smps was isolated from main ac line.
look at the rigol smps on the attachment , the y caps behind the transformer , show the isolation between primary and secondary.
so what's the main reason for usage of isolation transformer ?
anyway , my scope power consumption is 50w , is the 100w isolation transformer ok ?
Last edited by TO-247; 07-02-2011 at 08:46 PM.
"DIYSMPS"DANGER ! HV AROUND , DEATH is PERMANENT
Thats a very good question indeed.
At first, i never used isolation transformer, and only connected my oscilloscope to the mains line 220VAC without GND.
one day, I was measuring the signal at IGBT, and i started to hear a noise, like hssss. then..
BLOOOOOM, huge spark came from my oscilloscope, and every thing WENT OFFLINE.
I was scared to death barbecue of my 1400US$ oscilloscope
On later test, I thought it was a mistake from me, and I insisted to repeat same test!!
then, BLOOOOOM
After that, I tried to investigate what the hell is going on, If you look carefully. in real life
You are connecting the live GND of your SMPS -320VDC to the Scope GND.
And for some reason, Varistor in oscilliscope blown two times.
For me, I cannot tell the exact reason for my scope varistor blow.
But its clear, connecting - or + 320VDC line to oscilloscope, WHILE oscilloscope itself is connected to the mains 220VAC line, I don't think its correct thing.
read this statement, found in service manual of SMPS amplifier
"This will result in about 320Vdc between ‘LIVE GND’ and +HT. ‘LIVE GND’ is named as such
because it is not isolated from mains but it is the reference point for the PSU. If you need to
stick a scope probe around the primary side with the unit plugged in you must connect mains
via an Isolation Transformer. Without this, at best you will only trip your RCD breaker, at
worst you or your scope may not live to regret it. Do not forget that 320Vdc is still pretty
shocking whether it is isolated or not."
100W ISOLATION TRANSFORMER IS GOOD
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