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Making a timer for a grinder
oldgrumpus
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Posted on 07/11/2024 8:10 PM
So I could probably buy one, but then what satisfaction would there be by just doing that? Besides, this is also therapy for brain atrophy prevention. Another motivation is my obsessive determination for find uses for the stuff I have laying around the garage.

Goal: To push a button and have the grinder turn on for the specified amount of time and shut off. In the event of a power failure, the grinder must not cycle when the power is restored.

I have two nearly identical timer relays. One would be ideal for this purpose but it is already in use elsewhere. The second can potentially be used, but as stated above, the grinder must not cycle on during a power interruption. Unfortunately, that is the recommended way this timer is supposed to be reset as stated on the instruction sheet.

It occurred to me that a momentary push-button switch might be used to close a circuit to the coil and the relay might hold the coil on until the time cycle is completed. That would solve it all, but my brain atrophy has progressed far enough that it hurts me to figure it out. If you're able to see a way, I'd be most grateful.

The addition of a latching relay is possible, but I'd like to see if it is possible without going in that direction.

Thanks!!

Ralph
oldgrumpus attached the following images:
relays2.jpg relays1.jpg
Clever Coffee Dripper
Grinder: Macap M4
Roaster: Completed drum roaster project photos shown here:
Photos https://goo.gl/ph...Da6K4wfqw5
Videos https://www.youtu...Bd1NrdpSUH
Build thread https://homeroast...post_38189
 
Yasu
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Posted on 07/11/2024 11:47 PM
I also wanted a timer for my grinder and made a timer using an inexpensive board like the one attached!

https://www.aliex...4itemAdapt
 
renatoa
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Posted on 07/12/2024 7:29 AM
next challenge: grind by weight ? woohoo
 
allenb
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Posted on 07/12/2024 8:21 AM
Ralph,
Any chance you could post an image of the data sheet or something where we could see the actual schematic drawing of the timer you will be wanting to use. This would allow determining if it's possible to set it up without resorting to the external isolation relays. ThumbsUp
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgrumpus
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Posted on 07/12/2024 9:42 AM
Yasu, doesn’t this board also need a line voltage power supply? Are the relay contacts rated high enough for a grinder?
Edited by oldgrumpus on 07/12/2024 9:46 AM
 
oldgrumpus
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Posted on 07/12/2024 9:46 AM
Renatoa, yes! That would be ideal but since I am not quite at that level of OCD, I’m fine with a timer. 😁
 
oldgrumpus
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Posted on 07/12/2024 9:51 AM
allenb, I will see about the printed ones. I only have paper for the one I want to use, so I guess that works. Will dig it up and post it.
 
Yasu
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Posted on 07/12/2024 1:19 PM
A DC power supply is required separately, but an AC-DC adapter that had fallen into the house was sufficient to supply it, as it can have a very wide range of 5V to 30V.
The relay has a capacity of 10A, so 110V would be enough to drive a grinder of about 1KW.
 
oldgrumpus
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Posted on 07/12/2024 5:18 PM

Quote

Yasu wrote:

A DC power supply is required separately, but an AC-DC adapter that had fallen into the house was sufficient to supply it, as it can have a very wide range of 5V to 30V.
The relay has a capacity of 10A, so 110V would be enough to drive a grinder of about 1KW.


I saw these on eBay and considered it, but like I said, I'm obsessive about using stuff I already have. I do like this and see some potential uses for my projects. Thanks for suggesting!
 
oldgrumpus
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Posted on 07/12/2024 5:21 PM

Quote

allenb wrote:

Ralph,
Any chance you could post an image of the data sheet or something where we could see the actual schematic drawing of the timer you will be wanting to use?


Here it is:
oldgrumpus attached the following images:
6a854side2.jpg 6a854side1.jpg
 
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