How to Wire in Series

[tangocharlie123]

Hi

Can some one please advise if I have wired my pause switch correct. I have 2 momentry switches with N/O, N/C and C.

I have found various sites showing wiring diagrams and have followed the but I am un able to get a reading on a multi meter when either button is pushed.

I have wired the switch this way.

first switch
+5v from BoB to( N/O,C )to N/O on the second switch then C on second switch to ground on the BOB.

I am planning 4 switches in series so if I can get the first 2 working the rest should be easier.

With Thanks
Pete

[Richards]

When switches are connected in series, you need to use the N/C and the Common connections on the switches. When ALL of the switches are at rest (closed), you will have continuity between the contact points and a signal will be detected. When any ONE of the switches is activated (open), no signal will be detected.

When switches are connected in parallel, you need to use the N/O and the Common connections between the contact points. When ALL of the switches are at rest (open), you will have no continuity between the contact points and no signal. When any ONE of the switches is activated (closed), a signal will be detected.

(The explanation is assuming that when at rest, the lever is NOT being pressed. If the lever is being pressed with the switches are are rest, then use the N/O connection point for series and the N/C connection point for parallel.)

[JamesJ]

Pete check this thread for your answer. I found it by using the forum's "search" function. Good Luck!

http://www.mechmate.com/forums/showthread.php?t=281

[Richards]

Here's a schematic showing the difference between four switches connected in series and four switches connected in parallel:

[qroger]

Mike,
I have two questions for you:
1. Does the switch chain just supply a signal to the Gecko, thereby requiring low amperage,light service wiring, switches, etc.?
2. Did you draw your diagram in a word processor, then save it as jpg or similar?
Thanks
roger

[Richards]

Roger,

The schematic shows a low voltage, TTL level signal. TTL means a few milliamps (less than 10mA). Most 'old fashioned' TTL signals expected a LOW signal to signify 'Active'.

The Series connection is a classical 'AND' function, which means that Switch 1 AND Switch 2 AND Switch 3 AND Switch 4 must all be closed for the LOW signal to be seen.

The Parallel connection is a classical 'OR' function, which means that Switches 5-8 need to be Open (Off) for the Inactive HIGH signal to be seen. If Switch 5 OR Switch 6 OR Switch 7 OR Switch 8 is Closed (Active), then the output is Low (Active).

High voltage signals can also be used to directly control the coil of a Contactor or Relay. The E-Stop switch is usually a high-voltage signal. Limit switches, outputs from proximity sensors, and most push-button switches are usually TTL level. They are designed to interface to a low voltage circuit board. Be careful about using switches on the DC side of high current circuits. If a switch is used between the power supply and the stepper motors, you will have VERY high current for a few milliseconds after the switch is opened. That high current can destroy the stepper drivers. Putting the E-stop switch on the AC side of the circuit shuts down the motors properly, even though it may take some time before the power supply drains down enough to fully stop the motors. That is the reason that limit switches are normally low current devices that send a signal to the Break-Out-Board. A properly designed Break-Out-Board should have an input signal that controls the Gate or Output Enable signal of the chip that sends the pulse (step) signals to the stepper drivers. When the Output Enable or Gate is inactive, the pulse stream stops immediately.

The schematics were drawn with the free software ExpressPCB and then saved as a BMP (bitmap) file. Finally, I used GIMP to resize the BMP file.

[tangocharlie123]

Thanks to all with the advice on this after being away for so long I got it to work and now on to the next wiring setup.

Cheers
Peter