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ante
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Posts posted by ante
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I don’t really see a computer PSU as a DC-DC converter, more like an AC- DC converter or primary switched DC-supply. I believed computers where more sensitive than they obviously are since they seem to accept dirty (cheap) DC. I have seen many HiFi stereo amplifiers with only a pair of rectifiers and some electrolytic caps barley filtered at all and still no hum. In one resent case (a receiver 2X100W) which only had 2X2200uF on each side of zero, 55 Volts at standby and about 45 V - 4A at 80W output. I mean if they can get away with this it cannot be very critical!
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Yes with the LM350
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Do you think so; well it’s a complete PSU not just the pre-regulator!
It isn’t a paper towel, it was my scanner set on color on a gray scale pic! ;D -
I found it, this one worked very nicely:
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OK, so you mean this : http://electronics-lab.com/projects/power/011/index.html
That’s an interesting approach; I remember I have tried something similar once. I’ll see if I can find the schematic. -
Where I live I can buy a computer PSU (450W) for less than $20US. As everyone knows they are multiple voltage PSUs very compact and light. It shouldn’t be difficult to produce say a 2 X 40V 2 X 8A for the same amount and with the same physical size.
BTW. A 40V 40A unit is not a bench PSU it’s a welder! ;D -
How about Q2s base? Just left open? How does this work?
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Hi Zeppelin,
The 100% load swing means that a current swing (in this case) 0 to 5A creates less than 10mV change in the output voltage and less than 5mA in the output current!
Ripple at nominal load (in this case 5A) is +- 15mV RMS.
Not bad, I’d say! ;) -
Yes I know what you are getting at; it’s not the first time this discussion has been up! ;D
Let’s do it your way; let’s change the resistor for a 120R and we’re really safe! ;) -
Hi Paul,
Welcome to our forum.
The heatsink you need shouldn’t be inside the case anyway to be most effective! To help you more in detail we need the schematic to see what could be changed. -
Maybe nobody has a clue what you are talking about!
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Hi AG,
Well, Gary built and tested it without any problems! -
Hi Trigger,
I have to disagree; when I was looking for a bench PSU I found that a linear one with the same data was twice as expensive as the one above! -
Hi kebloks,
Welcome to our forum!
Looks good, try it! -
I believe it would work more reliable with only one LED in series with each transistor since the voltage is low.
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Hi Shahriar,
I don’t know what to explain but if you keep the electromagnet cool of even better super cool then it will be more powerful. -
Hi Zepplein,
Here is some info about my bench PSU, I’ve got the one with 0 – 40V & 0 – 5A, it’s also available as 0 – 20V & 0 – 10A.
http://www.kjell.com/filarkiv/SUPPORTPDF/41-50/44/44311/44311.pdf
Here is another one similar with a different name on it: http://www.elfa.se/elfa-bin/setpage.pl?http://www.elfa.se/elfa-bin/dyndok.pl?lang=en&dok=5645.htm
Works really well too! ;)
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OK Nick, I did misunderstand your question! :-[ I thought you needed regulated (limited) current for the LED’s! I can see now you are using a resistor for this.
So this circuit does not work? What is trigging the base of the transistor? -
The motor does not have to be bigger to be stronger, the magnets and the armature winding decides the torque and power. You can re-wind the rotor (armature) with less turns of a greater gauge wire to get more power.
It will of curse consume more power from the batterys too! ;) -
Hi Nick,
Why not use the LM317 or LM350? -
Hi Nick,
It depends on the power dissipation in the LM323 and the available current on the input side! -
By lowering the temperature of the core and coil you can get some more magnetic power.
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Your best choice is to find the webpage for the battery manufacturer and you will get the correct information.
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A telephone line has a bandwidth of only 3kHz if you are lucky.
It depends on how you use the phone line; my Internet connection, which uses the phone line, can transfer 24Mb/s (ADSL)! This is enough to watch live TV transmission in full screen with stereo sound in HiFi! ;)
motor driver L298 help
in Electronic Projects Design/Ideas
Posted
Hi AG,
That’s correct but; the torque does change long before this point (and thus the rpm under load) due to the inductance of the motor winding. When constructing a PWM controller for a motor there is some consideration regarding the frequency vs the inductance. This means that you need to know in which rpm range you are using the maximum torque when deciding the frequency.
If you need to change the rpm without changing the pulse length it’s done by the amplitude.