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Electrical engineering
Course: Electrical engineering > Unit 7
Lesson 1: All about Spout- 3rd graders build robots at Santa Rita Elementary School
- SPDT switch
- Spout's sliding SPDT switch
- Spout lights
- Spout motor
- Spout battery configuration and polarization
- Spout's reversing circuit and final assembly
- Spout circuit
- Rotary switched spout circuit
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SPDT switch
Created by Karl Wendt.
Want to join the conversation?
- Where can i find a SPDT switch in every day life?(4 votes)
- Most arcade style button has a SPDT switch in it.(1 vote)
- I didn't quite understand how did you turn it on and off.(4 votes)
- The contact connected to the pole is touching one throw usually but when to depress the lever the contact stops shorting the first throw and shorts the second throw so energy flows through it now. So if this switch is placed in a circuit on part goes to the pole the other goes to the normally open throw so when the switch is pressed energy can pass through and the motor turns on.(3 votes)
- what can the SPDT switch be used for ?(3 votes)
- Hello Santiago,
My favorite application of a SPDT switch it the two-way light switch that is found in many homes. Ref:
http://www.instructables.com/id/Three-Way-and-Four-Way-Switches-How-They-Work/
Regards,
APD(3 votes)
- What's the difference between a closed and open circuit?(1 vote)
- Hello Matthew,
Closed circuit indicates that there is a complete electrical circuit - the system is operational.
Open circuit indicates that the electrical circuit is incomplete - the system is dead. Pull the outlet out of the wall socket is one way to "open the circuit."
Regards,
APD(3 votes)
- Where can I find this kind of switch in India?(1 vote)
- why did you take the lever apart(1 vote)
- How can we change speed of a simple single phase induction motor?(1 vote)
- By giving it more power. Like something about electricity . More speed cost more ingine wheel(1 vote)
- my video isn't working WHAT DO I DO!(1 vote)
- why won`t my video load?(1 vote)
- why do the videos take a very longer time than the first one you saw? this one is not even working.(1 vote)
Video transcript
OK, so we're going to take a
look inside of the single pole, double throw lever switch. So we have one pole right
here and two throws. And what that basically
means is that we can connect to three different
locations on this switch and control the power
in two circuits. So we're going to take a little
small watchmaker screwdriver and pry open the housing. OK, so this is the inside
of our lever switch. You can see it's all
taken apart for us. And there are two contacts here. There's one pole
here and two throws. And so what that means is
when the switch is open, it can let the power
flow in one circuit. When it's closed, it can let the
power flow in another circuit. Or it can just
close that circuit. So you can see what happens is
there's a little tiny plastic hammer here that pushes
against the spring, so the lever causes the spring
to push down on this copper contact. And that is switching between
this side and this side. So the switch is basically
opening and closing the circuit between
this side and this side, and then between this
side and this side. So if you watch carefully,
you can see that little copper contact shifting up and down. I believe these pieces
are made out of aluminum. It looks like this
spring is spring steel. It looks like we
have the lever here, which is probably nickel-plated
steel, it looks like. And we have a copper
contact that the spring is connected to. And I think the housing
is made out of ABS. And again, that's an
injection-molded housing. You can see that it's got
these little spikes here that stick up. I'm not sure if you
can see that too well, but there's little spikes there. And they basically go through
the top of the housing here in these little tiny holes. So if we put this like
this, that's how it goes. And those little tiny spikes
will stick through those holes. And then what
they'll do is they'll take a hot plate or
a hot piece of steel and push it against those spikes
that are sticking through. And they actually mush down
like a mushroom on top of this and hold it in place. And so that's what the top
of our single pole, double throw lever switch,
how it's held in place. And again, that looks like an
injection-molded piece as well. So again, when we
push the lever switch, it switches between
this contact. This contact is
always connected, but it switches between
these two contacts. So there's single
pole-- this is the pole, and there's two throws. So you can see these
two throws are there. And when the switch
gets bumped, it switches between those throws.