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Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
You have zero chance of building your own SCR unless you have sophisticated equipment and a clean room. There are alternatives, but SCR's are the cheapest one.
Registered Member #1497
Joined: Thu May 22 2008, 05:24AM
Location: Toronto, Ontario, Canada
Posts: 801
Essentially, you cannot build a SCR from a hobbyist perspective. What is the application and voltage/current ratings that you'd be looking for, perhaps we could help figure out the best part to use
Registered Member #1819
Joined: Thu Nov 20 2008, 04:05PM
Location:
Posts: 137
If you're talking about assembling SCRs from other pre-built discretes, you could use a NPN and a PNP transistor in tandem (look up the internal structure of an SCR on Google). But I doubt tha you will ever find a transistor with a 1200V 5000A peak rating for under $1000, if they even exist.
Registered Member #90
Joined: Thu Feb 09 2006, 02:44PM
Location: Seattle, Washington
Posts: 301
Pyromaniac wrote ...
I was wondering ... is there an alternative to SCRs?
Assuming you're building a coilgun, there are other mechanical and solid state alternatives to SCRs. In no particular order, you may also consider:
MOSFETs
BJT (bipolar junction transistor) ie. just a big standard transistor
IGBT (insulated gate bipolar transistor) ie. golf cart motor controllers
household light switch
large relay or contactor
slam two copper surfaces together with a heavy spring
triggered spark gap
We often choose SCRs because they are relatively inexpensive, high power, low resistance, reliable and easy to trigger.
Research this list, they all have their own advantages and drawbacks in performance and cost.
I've always used SCRs in the past for convenience and low cost, but I'm in the process of building my own solenoid-actuated contactor of a novel design for my kilojoule coilgun. In theory it will achieve much lower resistance than any solid state device. In practice it's cost over $100 in parts so far. I have some ideas about solving the contact bounce problem, but we'll have to wait and see how this turns out.
Cheers, Barry Now that I'm older I thought it was great that I seemed to have more patience. Turns out I just don't give a shit.
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SCRs
I have some ideas about solving the contact bounce problem, but we'll have to wait and see how this turns out.