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I want to make a circuit to change 12 Volt DC Motor direction and move some thing between two points. Using Relay or some basic limit switches.Like this Image.

I got a Circuit As i want...

AUTOMATIC FORWARD-REVERSE A MOTOR

The following circuit allows a motor (such as a train) to travel in the forward direction until it hits the "up limit" switch. This sends a pulse to the latching relay to reverse the motor (and ends the short pulse). The train travels to the "down limit" switch and reverses.

enter image description here

If the motor can be used to click a switch or move a slide switch, the following circuit can be used:

enter image description here

Please Help me to understand this circuit and how to wire these things.

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Something like this should work. Note that the limit switches are different- one is normally closed and the other is normally open. If you have a relay with three form C contacts you can avoid using the diodes.

schematic

simulate this circuit – Schematic created using CircuitLab

The two contacts are used to reverse the motor in the usual way, but one contact does double duty as a self-hold for the relay. The diodes prevent SW2 from shorting out the supply when the relay is de-energized and the limit switch to engage the relay is activated.

You can put a bridge rectifier across the motor to absorb inductive spikes from the motor inductance.

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  • \$\begingroup\$ Can you tell me this circuit using SPDT 5 Pin Relay because of i can not use Latching Relay or any other Special type Relay in circuit. \$\endgroup\$ – ANKIT JAIN Jan 4 '15 at 15:17
  • \$\begingroup\$ You can use two SPDT relays with the coils in parallel rather than a DPDT relay, In either case they are normal relays (not latching). \$\endgroup\$ – Spehro Pefhany Jan 4 '15 at 16:22
  • \$\begingroup\$ Please send me the full circuit using 2 SPDT Relay and 2 limit switches. \$\endgroup\$ – ANKIT JAIN Jan 5 '15 at 12:11
  • \$\begingroup\$ See above- the two SPDT relays with coils paralleled are the same as the DPDT relay for this purpose. \$\endgroup\$ – Spehro Pefhany Jan 5 '15 at 14:58
  • \$\begingroup\$ Thanks for this Single relay circuit. This circuit works fine with 9-12Volt. Is there are any other ways for this circuit works for less then 6V which is lower then Relay coil Operating voltage. For the same DPDT Relay. \$\endgroup\$ – ANKIT JAIN Feb 2 '15 at 7:31
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Maybe something like that could work.

Switches are on the two ends and trigger the change of direction of the motor.

The relay should be of the 'latching' a.k.a. 'bistable' type.

schematic

simulate this circuit – Schematic created using CircuitLab

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  • \$\begingroup\$ That relay isn't going to last very long switching an inductive load like that. \$\endgroup\$ – Phil Frost Jan 2 '15 at 19:44
  • \$\begingroup\$ @Fhil Frost : Yes. Snubber diodes, capacitors would be really useful for avoiding sparks... \$\endgroup\$ – TEMLIB Jan 2 '15 at 20:22
  • \$\begingroup\$ @spehro-pefhany and TEMLIB Sorry to say but in your circuits the switch SW1 and SW2 are something like push button switch or on/Off switch but i want auto switching without any manual switching so the motor/hardware goes at end point the polarity change and motor come back reverse. \$\endgroup\$ – ANKIT JAIN Jan 3 '15 at 2:59
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    \$\begingroup\$ The switches are sensors for detecting the tray position. They can be actual press buttons, reed switches and magnets, proximity sensors, optical barriers... The alternative would be to have a fixed temporisation : 1 minute to the left, 1 minute to the right... \$\endgroup\$ – TEMLIB Jan 3 '15 at 11:14
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    \$\begingroup\$ @ANKITJAIN Both TEMLIB's and my circuit are fully automatic- the switches are limit switches that detect the end of travel in either direction. Microswitches are often used for this purpose. \$\endgroup\$ – Spehro Pefhany Jan 4 '15 at 11:44
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enter image description here![reversing a dc motor][2]

This is a minimal reversing circuit for a dc motor. It is missing a stop button, start, and interlocks, and it can all be added to it. It doesn't start on it's own, one limit switch has to be pushed. The circuit has a dc motor, 2 relays, and 2 limit switches. The interlocks are important, because if the 2 relays are energized at the same time, it is a short circuit. As drawn, the whole circuit is on a same voltage (relay coils would be same voltage as the motor). The bottom part can be separated, and then the motor can be a different voltage than the relay coils. Normally a circuit like this also uses additional overtravel limit switches, in case the two fail.

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  • \$\begingroup\$ please explane the circuit and which are the relay and which are the switches. \$\endgroup\$ – ANKIT JAIN Jan 3 '15 at 15:24
  • \$\begingroup\$ There are 2 relays, "for" and "rev". Each has 3 normally open contacts relay contact looks like this ---------||-----.There are 2 limit switches, each utilizing normally open and normally closed contact. Both the limit switches receive power to the common connection, the normally open is wired to the opposite direction relay coil, the normally closed contacts supply power to the relay holding contacts. \$\endgroup\$ – sparky Al Jan 4 '15 at 5:26

protected by Nick Alexeev Apr 10 '17 at 14:15

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