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How to connect SPDT relays to control a motor's direction?

I have two SPDT relays, but I don't have much info about them: [a: side label] & [b: top label]

a) 8A - 250VAC

    10A - 28VDC

    DC - 5V

b) Coil: DC 6 9 12 24V

    Capacity: 5 8 10 15A 250VAC

I also have some transistors like this one, some old circuits with various types of resistors, and some diodes too.

How should I connect these things to make a motor change its direction?

My goal is to control the speed and direction of the motor; I already did the PWM with a E13007 transistor and it worked fine. If you need more details, just ask. Thanks.

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Have you looked over the schematics here on LMR? If you connect the coils in parallel, and switch them with a transistor similar to what is shown, it should work ok.

BOA's schematic in the H-Bridge Matrix node has a note saying it is wrong. Where could I find the corrected one? Also, the image links are broken...they require you to login. I can't see the breadboard view of the circuit.


I have the coils connected in series...is this wrong?

SPDT Relay:  [+] are contacts / weird symbols are the coil / O's are the motor contact points

      COM                 COM       

|       +       |       |       +       |

|1   -_-_-   2|-------|1   -_-_-   2|

|                |       |                |

|   +      +   |       |   +      +   |

   NC    NO           NC    NO

     |        |____O___|        |

     |______O___________|

 Here you can see my relay setup: 2 connects to 1 and the two coils are supposed to act as one. 

Thanks for replying.

Perhaps you could look at the next h-bridge down that page, the Modified version of BOAs for a corrected version.

Can't remember who decided to host those images on their server, but the links do appear to be down. Perhaps they can be brought back to LMR and linked properly again.

 If you connect the relays coils in series, you require twice the voltage to activate them. So if they are 5 volt coils, you'll need 10 volts. If in parallel, twice the current, which a good transistor interface should be able to handle.