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frankwas

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Posts posted by frankwas

  1. Hi all.

    I am busy working on a project that will turn a disc, just a plain steel disc with a rod attached to it to simulate a steam train's piston action. I am now looking for the right type of motor for this. The disc is approx. 1 kg, possible less. I want to know if a stepper motor might work and will it be strong enough? Or what type of motor would you suggest cause I'm not good with the torque specs and don't know how much it can pull.

    Thanks!

  2. Hi All!

    Ante, if you're reading this I might have found a solution to that other laptop project.

    Can anyone please tell me if it's possible to build a circuit that can be connected in parallel somehow with a normal ethernet cable, and then drive an led that blinks on transfer? Like the activity LED on a hub or lan card?

    Thanks!

  3. Hi all.

    Can someone please help me. I have an old laptop that I want to make REALLY portable. I want to take one or two 12V batteries and run my laptop from it. The problem is that the laptop needs 16V at 3.5A. Do you have any suggestions on how I could do this? I'm not expert but I was thinking about using some sort of voltage regulator that puts out 16V at about 5A or something. But will my laptop last long when using this battery, because it puts out 17Ah at 12V so it should hold for a while at 16V shouldnt it?

    Thanks!

  4. Hi all.

    Can anyone please help me with the following: I want to power a car amp from my mains power supply (220V, 50Hz). I have read and searched around, but haven't found anyone that could really tell me exactly how to do this. My idea was that I take a powerful PSU, about 600W or so and strip all connectors off and connect the yellow wires together and the black ones and connect it like that. However, I read somewhere that you could also "bridge" two PSU's together by connecting all yellow wires from both PSU's and all black ones. They mentioned using diodes on the yellow wires rated at at least 10amp or so.

    Can anyone please tell me how I could do this by using one or two PSU's or would you suggest another method. I'm on a very tight budget and can't afford the large, proper high current ac/dc converters.

    Thanks in advance!

  5. Hi All!

    I haven't been here for a while! How is everyone doing? I just want to say thank you to everyone who posted replies to all my other questions and topics I had! I really appreciate it!

    I have a new, small project that I would like to build. I have searched for a while now but didn't find anything useful. I want to build a circuit that interfaces with a normal telephone and that I can connect a normal PC headset (two speakers, one mic 3.5mm jacks), with a switch that I can choose between the normal handset or the headset.

    Can anyone please point me to a website or a circuit that might help me?

    Thanks!

  6. Hi All!

    Just wanna say thank you to all that have helped me on the other project for the power supply for the amp. This is actually a supplemetry post for that amp psu.

    I was wondering if anyone has some ideas how I can build a 0 - 60A dc digital ammeter because I want to find out exactly how mush juice my car amp pulls at full power and then permenantly use the ammeter for a nice effect. Can anyone please help point me in the right direction, because I am lost when it comes to ammeters. All I know is that they need to be connected in series and you get something like a shunt but I have no idea how and where to use it.

    I have built this kit http://kitsrus.com/pdf/k61.pdf and used it perfectly for a digital voltmeter, but is there a way that I can convert it to the desired ammeter?

    I found this kit: http://kitsrus.com/pdf/k34.pdf. On page 3 they explain how to convert the kit to display amps. However, I have worked out on a 200mV reference, I would need a 0.003ohm resistor! And the other way around if I use a 1ohm resistor then I would need a 60V reference! Can anyone please help?

    Thanks.

  7. Hey.

    Ok, that sounds about exactly what the amp is made up of. I'll hook it up and then see what I get and post back. I also need to get a cam for the snapshot. As soon as I have done this, I will post back as soon as possible! The amp isn't 1400W rms, the RMS of the amp is about 300 - 400w at the most. I will be playing two 125W rms subs (each) at about 80 percent power.

  8. Hi all!

    It's been a while since I last posted here. Thanks for everyone that helped on my previous designs!!!! Now, I have yet another idea that I want to build. I have been searching around the net for a car amplifier psu but  to no avail. I found a psu that uses TIP transistors with a 24V 35A transformer. Correct me if I'm wrong but isn't that a 24x35 = 840VA transformer? They are rare where I live. The closest I can get is a 50V 1000VA and it is very expensive!

    Let me get to the point! I have a 1400W (about 250Wrms) car amp lying around that I would like to power from my house power, 230V. I thought that if I take a transformer that is say 300VA, 12V, use a bridge rectifier with a 400VA rating and a nive juicy capacitor, wouldnt that be sufficient? Please help me if I'm completely off track.  :P

    Thanks in advance!!

  9. Hi All!

    Thanks to all for your input on my previous project's questions. Now I have a new one, very small actually and I'm sure a lot of you will be able to solve it within minutes.

    Speaking of minutes, I would like to build a digital 7 segment clock, from a kit or whatever, then have it switch on a relay momentarily (for about 1 - 2 seconds) for every minute it advances in time and then carrry on as usual.

    Is this easy or diff to build?

    Thanks.

    Francois.

  10. Hi All.

    I am really intereste in building a touch sensitive controller for my room. But, I want to make it look awesome. I was wondering if it is possible to make a circuit that can pick up touch through glass or plexiglass or similar? Does anyone know where I could look for a circuit or anyone point me in the right direction. I looked for a few circuits, but they all require the person to physically touch an open metal contact.

    Regards,

    F.

  11. Hi guys! Sorry for the silence. Had a lot to do! I finally finished my amps and speakers. Just need to finish off my speakers. As soon as I'm done i'll post photos. The sound quality is phenomenal!!!! I would really recommend if anyone wants to build a cheap, good quality amp the lm3886TF is the best!

    Thanks for all your inputs! I really appreciated it! Now, onto the next project :)

  12. I just hooked up my sub to one of my 3886 amps and it played it perfectly!!!

    But now, I have two transformers that I would really like to use so that I can connect two more amos to it. The one is a 20-0-20 3.2 A per secondary winding. Will I be able to use this one to power the amps just like the origianl 160VA I used? Because I remember that you said earlier that the voltage would be too high for the amp to handle, but what if I get some way to lower the voltage? The other transformer is a 30-0-30 5A per secondary transformer. What would you suggest I do?

    Thanks!!!

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