Momentary buttons for Dins

[MattB]

Hey guys,

I'm new here and gathering all the parts for my control panel build. I'm using a BCS-462 and have just about all the components but have a question about the Dins and the buttons I can use.

I want to put 8 momentary buttons on the control panel face. Do they need to be rated at 5V? I have seen some illuminated buttons which look nice but are $$. If I use non-illuminated will they need to be 5V rated? What have you guys used?

(on a side note - any ideas for assigning actions to the Dins? Alarm reset, HLT warm up, etc?)

Cheers!
Matt

[JonW]

Ratings on switches are for the max current the switch can handle. You can use 120V/20A switches if you wanted - you are not limited to needing switches that say 5V. If you get illuminated switches, that is a different issue and you need sufficient current to power the LED or lamp in the switch.

I personally wouldn't put 8 switches on the control panel unless you have specific uses for them already. I currently don't use any on my system, but previously I used one for cancelling the alarm and another for firing the igniters. I've changed all of my alarms to short alarms, so now I don't need to cancel them. I've also switched to hot surface igniters instead of the spark igniters so I never need to manually re-ignite. I do still have on-off-on switch wired into the BCS for my fermenter so I can switch it to ferment mode or crash-cool mode without having to pull up the BCS interface.

[oakbarn]

If you are going to use DINS, I would suggest that you do not get momentary ones except to cancel an Alarm (See Ladder Logic in the Wiki). The DINs are mostly used in Ladder Logic and if momentary will trigger the Ladder Event only while depressed. You can basically make a toggle switch momentary by one shot. (You can "reset" simply by cycling the switch off).

I have ordered some 5 vdc LEDs and will see if they work as the amperage of the 5vdc output of the BCS is small. (300mA).

Most Illuminated switches that have 2 NO contacts are 120/240 vac which is not a good idea to use.

[JonW]

If you are going to use DINS, I would suggest that you do not get momentary ones except to cancel an Alarm (See Ladder Logic in the Wiki). The DINs are mostly used in Ladder Logic and if momentary will trigger the Ladder Event only while depressed. You can basically make a toggle switch momentary by one shot. (You can "reset" simply by cycling the switch off).

Contrary to what Oakbarn suggests above, momentary contact switches are quite useful with the BCS. In fact, most situations of using DIN's would be with momentary switches. In addition to using them in ladder logic, you can use them as an exit condition for any state. It makes no sense to require someone to turn a switch on and off when a momentary switch would have accomplished the same task with a simple push.

I have ordered some 5 vdc LEDs and will see if they work as the amperage of the 5vdc output of the BCS is small. (300mA).

I would suggest using switches where the LED's are being powered from a separate power supply than the BCS. You not only have more flexibility in what types of LED switches you can use, you won't have any issues with over drawing the current rating of the BCS.

Most Illuminated switches that have 2 NO contacts are 120/240 vac which is not a good idea to use.

The contact rating of a switch is of no consequence for the switching needs of the BCS since it is such low current and voltage. If you are talking about the actual illumination of the switches being powered from 120V, then I would agree - that is a bad idea. No sense in having high voltage LED's running in the same switch as all your low voltage switching.

[oakbarn]

If you are going to use DINS, I would suggest that you do not get momentary ones except to cancel an Alarm (See Ladder Logic in the Wiki). The DINs are mostly used in Ladder Logic and if momentary will trigger the Ladder Event only while depressed. You can basically make a toggle switch momentary by one shot. (You can "reset" simply by cycling the switch off).

Contrary to what Oakbarn suggests above, momentary contact switches are quite useful with the BCS. In fact, most situations of using DIN's would be with momentary switches. In addition to using them in ladder logic, you can use them as an exit condition for any state. It makes no sense to require someone to turn a switch on and off when a momentary switch would have accomplished the same task with a simple push.

I would agree that momentary contact switches can be useful depending on what you want it to do. As probably the most common "use" is to switch states in a process, the momentary would be better. I think there is a place for both. I use more toggles than momentary the way I have set my processes. You can setup Ladder Logic where more than an single DIN must be TRUE with Toggles. I am sure some people may have no toggles. That is the great thing about a product like the BCS. It can conform to you in some cases and not force you down a single path.

I have ordered some 5 vdc LEDs and will see if they work as the amperage of the 5vdc output of the BCS is small. (300mA).

I would suggest using switches where the LED's are being powered from a separate power supply than the BCS. You not only have more flexibility in what types of LED switches you can use, you won't have any issues with over drawing the current rating of the BCS.

I do not disagree with this at all. The LEDs never came from China so I never got to test them. I have since done exactly this (12 vdc powered LEDS with different power supply) using different switches.

Most Illuminated switches that have 2 NO contacts are 120/240 vac which is not a good idea to use.

The contact rating of a switch is of no consequence for the switching needs of the BCS since it is such low current and voltage. If you are talking about the actual illumination of the switches being powered from 120V, then I would agree - that is a bad idea. No sense in having high voltage LED's running in the same switch as all your low voltage switching.

I was not really clear here. I was suggesting that you do not really want to use 110/220v just to illuminate an LED as that voltage can be dangerous to a brewer. I have used heavy duty toggle switches that are rated for 240v to switch a DIN without any issues.