S slingsrat New Member May 2, 2009 #1 I need a very simple circuit diagram for a SCR switch. I need it so when a circuit is broken power flows through a secondary circuit. All the scr switch diagrams I've found work with an already broken circuit and connecting it will trigger the scr. Basically I want a circuit that will trigger a solenoid when a circuit is broken. I used an scr design in the past but have forgotten it! Thanks for any help.
I need a very simple circuit diagram for a SCR switch. I need it so when a circuit is broken power flows through a secondary circuit. All the scr switch diagrams I've found work with an already broken circuit and connecting it will trigger the scr. Basically I want a circuit that will trigger a solenoid when a circuit is broken. I used an scr design in the past but have forgotten it! Thanks for any help.
ericgibbs Well-Known Member Most Helpful Member May 2, 2009 #2 slingsrat said: I need a very simple circuit diagram for a SCR switch. I need it so when a circuit is broken power flows through a secondary circuit. All the scr switch diagrams I've found work with an already broken circuit and connecting it will trigger the scr. Basically I want a circuit that will trigger a solenoid when a circuit is broken. I used an scr design in the past but have forgotten it! Thanks for any help. Click to expand... hi, Connect the normally closed switch across the SCR gate and Cathode, connect a resistor from the Anode to the gate. When the switch opens the Gate will be triggered, choose a resistor with of the highest value that will trigger the SCR. Remember resistor wattage. Last edited: May 2, 2009
slingsrat said: I need a very simple circuit diagram for a SCR switch. I need it so when a circuit is broken power flows through a secondary circuit. All the scr switch diagrams I've found work with an already broken circuit and connecting it will trigger the scr. Basically I want a circuit that will trigger a solenoid when a circuit is broken. I used an scr design in the past but have forgotten it! Thanks for any help. Click to expand... hi, Connect the normally closed switch across the SCR gate and Cathode, connect a resistor from the Anode to the gate. When the switch opens the Gate will be triggered, choose a resistor with of the highest value that will trigger the SCR. Remember resistor wattage.
S slingsrat New Member May 2, 2009 #3 So this is correct then? **broken link removed** pressing the switch will power the solenoid? Last edited: May 2, 2009
ericgibbs Well-Known Member Most Helpful Member May 2, 2009 #4 slingsrat said: So this is correct then? **broken link removed** pressing the switch will power the solenoid? Click to expand... DONT connect it like that or it will fail!. Ill post a sketch
slingsrat said: So this is correct then? **broken link removed** pressing the switch will power the solenoid? Click to expand... DONT connect it like that or it will fail!. Ill post a sketch
ericgibbs Well-Known Member Most Helpful Member May 2, 2009 #5 hi, Look at this image. Once triggered, the SCR will remain ON until +V is removed. As you havn't said which type of SCR or what the +V voltage is, you will have to calculate the R value. Attachments esp01 May. 02.gif 6.5 KB · Views: 1,492
hi, Look at this image. Once triggered, the SCR will remain ON until +V is removed. As you havn't said which type of SCR or what the +V voltage is, you will have to calculate the R value.
S slingsrat New Member May 2, 2009 #6 Thanks for that. How do i calculate R? I'm using a C106D at 12V.
ericgibbs Well-Known Member Most Helpful Member May 2, 2009 #7 slingsrat said: Thanks for that. How do i calculate R? I'm using a C106D at 12V. Click to expand... hi, Looking at the datasheet, a 1.5K or 2.2K resistor should trigger OK. 0.125W or 0.25Watt.. To switch OFF the scr, place a normally open switch across anode to cathode [ short out the SCR when pressed]. OK.?
slingsrat said: Thanks for that. How do i calculate R? I'm using a C106D at 12V. Click to expand... hi, Looking at the datasheet, a 1.5K or 2.2K resistor should trigger OK. 0.125W or 0.25Watt.. To switch OFF the scr, place a normally open switch across anode to cathode [ short out the SCR when pressed]. OK.?