# question about powering solenoids for kinetic sculpture project

#### slatepipe

Joined Oct 2, 2017
23
hi there - first question on this forum. thanks
i have a question about solenoids. i have a project which requires using 10 push type solenoids, i have sourced one online which i think is appropriate - a 'push' type, 12v 1amp one. i will be controlling them using a Crestron touchpanel and processor. i am quite new to these principles and from what i can see of the solenoid i have found, there are two wires coming from it which i figure would go to a power supply and to the relay port on the processor which would act as a switch to turn it on or off. so, psu - relay output - solenoid, wired in a circle.
my question is : if i am to use 10 solenoids then is there some kind of mains supply which could supply 10 of them with power at the same time so that i don't have to buy 10 separate PSU's? there would be a maximum of all ten solenoids being 'on' at once. or is there some kind of wiring schematic which would allow for powering 10 solenoids from one psu? or am i getting the wrong end of the stick?

i hope this makes sense. many thanks for any guidance and advice

#### OBW0549

Joined Mar 2, 2015
3,566
my question is : if i am to use 10 solenoids then is there some kind of mains supply which could supply 10 of them with power at the same time so that i don't have to buy 10 separate PSU's?
Sure, there are plenty of 12 volt power supplies available that can supply 10 amps or more; they're inexpensive and readily available from many outlets, such as Amazon.com or Ebay. Here's one.

#### philba

Joined Aug 17, 2017
960
Is the 1A draw steady state? There will be an inrush spike so you need to factor that in. I'd plan for maybe 50% extra capacity and/or sequence the solenoids so they never start up at the exact same time. 10s of milliseconds apart may be sufficient. So maybe a 15-16A supply. You might want to consider having a spare as well if down time is not acceptable.

#### slatepipe

Joined Oct 2, 2017
23

so i guess a 10 amp psu wouldn't be a problem for the solenoids as they would only take the amount of power they need and wouldn't get overloaded with 10amps?

and i guess if i get one of these 12v 10amp psu's then i'd need a breadboard or something to route the power to each of the relay ports?

and if all the solenoids are 'on' then the max 10 amps would be being supplied? so would it be a better idea to get one with say, 12 amp max?

thanks again

Joined Jan 15, 2015
6,058
12 Volts at 1 Amp is 12 Watts so running all solenoids at once you really want about a 12 Volt 15 Amp capable supply or 12 Volt 180 maybe 200 watt supply. If all solenoids will always be on at the same time then a single relay can control all ten of them. I like automotive relays if you can use one. You need a relay with contacts rated for aabout 15 amps 12 volts DC. This would go better with a link to exactly what you have and data sheets.

Ron

#### slatepipe

Joined Oct 2, 2017
23
Is the 1A draw steady state? There will be an inrush spike so you need to factor that in. I'd plan for maybe 50% extra capacity and/or sequence the solenoids so they never start up at the exact same time. 10s of milliseconds apart may be sufficient. So maybe a 15-16A supply. You might want to consider having a spare as well if down time is not acceptable.
hi - thanks for this. i'm not sure what steady state is? does it describe when the solenoids are 'off'? if so then i figure each one will draw 1amp when they are turned 'on'.
i aim to press buttons on a crestron touchpanel which will activate different combinations of solenoids to press keys to produce chords on an accordion which is fixed to an automated hoist which pulls it in and out

so you're saying a psu with an ampage of a bit more than actually need is the best way?
thanks

12 Volts at 1 Amp is 12 Watts so running all solenoids at once you really want about a 12 Volt 15 Amp capable supply or 12 Volt 180 maybe 200 watt supply. If all solenoids will always be on at the same time then a single relay can control all ten of them. I like automotive relays if you can use one. You need a relay with contacts rated for aabout 15 amps 12 volts DC. This would go better with a link to exactly what you have and data sheets.

Ron
hi - thanks for this. this is all pretty new to me. i'm working on an interactive sculptural sound project which uses a Crestron CP2e processor with eight relay ports. Crestron stuff is normally used for room control with things like audio visual equipment, lights and screens etc. at the moment i have it controlling two hoists which go up and down. i am repurposing this equipment to make an interactive sound piece using an accordion. the hoists pull it in and out and the solenoids will press different combinations of keys to produce chords after various buttons on the touchpanel are pressed. i include the spec sheet for the cp2e processor if this could be a help. many thanks

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Joined Jan 15, 2015
6,058
Steady State just means will all 10 solenoids be on at the same time drawing a constant (steady state) ten amps? Now you also mention:
i aim to press buttons on a crestron touchpanel which will activate different combinations of solenoids to press keys to produce chords on an accordion which is fixed to an automated hoist which pulls it in and out
If this is the case each solenoid will need to be driven (turned On / Off) on an individual basis. Your controller output will determine what each solenoid is doing and when. Each solenoid can be driven by either a relay under control of the controller or a MOSFET device for switching the solenoids on and off at given times. If you anticipate all solenoids being on at any given time I would be thinking hard about a 12 Volt 15 Amp supply.

Ron

Joined Jan 15, 2015
6,058
OK, now I see what you have:
RELAY OUTPUT 1 - 8 (2) 8-pin 3.5mm detachable terminal blocks comprising
(8) normally open, isolated relays;
Rated 1 Amp, 30 Volts AC/DC;
MOV arc suppression across contacts

That should work fine and handle 8 solenoids. Was that what you planned to use?

Ron

#### slatepipe

Joined Oct 2, 2017
23
OK, now I see what you have:
RELAY OUTPUT 1 - 8 (2) 8-pin 3.5mm detachable terminal blocks comprising
(8) normally open, isolated relays;
Rated 1 Amp, 30 Volts AC/DC;
MOV arc suppression across contacts

That should work fine and handle 8 solenoids. Was that what you planned to use?

Ron

hi - this is a great help. i'm thinking of using ten solenoids (to mimic 5 fingers of each hand). i realise that this is too many for the relay outputs, and i am already using 2 of the outputs for the hoists. but i can use an adapter box (giving me eight more relay outputs) or i could change some of the other ports to use them for relay outputs too

so i just need to figure out the schematic routing to run one solenoid per relay output using one 10 amp psu (or 12-15 amps?). i dont think i would be turning all ten solenoids on at once as that would just create a racket, and i want to play notes and chords via the touchpanel

so 10 x 12v 1amp relays would be fine in conjunction with this processor?

thanks

Joined Jan 15, 2015
6,058
Your end result will look a little like the below drawing, just more relays out where I only show 3 Each.

I placed diodes across the solenoid coils to snub inductive kick. The board is rated for 1 Amp so for intermitent use the relay outputs you have should be fine. Questions just ask.

Ron

#### slatepipe

Joined Oct 2, 2017
23
wow. thanks for this. great stuff. now i need to buy some of these solenoids and find some kind of similar psu here in london. it all seems quite doable with the info i'm getting. thanks again. i'll post an update and/or ask some moroe questions over the next few days or weeks thanks

Joined Jan 15, 2015
6,058
More than welcome and maybe one of our UK members can suggest a supplier for the supply.

Ron

#### slatepipe

Joined Oct 2, 2017
23
https://www.ebay.co.uk/p/Ac-dc-110v...t-Switching-Power-Supply-Converter/1844430950

hi again - i found this on ebay uk and t seems to be very similar. can i ask if it will do the job of looking after up to 10 1amp solenoids? i figure yes, going on what i've been told so far but i thought i'd check before i click the buy now button. can i also ask if it is easy enough to fix a plug to for mains power as i'm a bit unclear as to where this wiring would go

https://www.amazon.co.uk/dp/B00HR8H38A/ref=pe_3187911_185740111_TE_item

i just bought 2 of these solenoids as well and if they work well then i'll buy the rest

thanks again

#### marcf

Joined Dec 29, 2014
260
Is the 1A draw steady state? There will be an inrush spike so you need to factor that in. I'd plan for maybe 50% extra capacity and/or sequence the solenoids so they never start up at the exact same time. 10s of milliseconds apart may be sufficient. So maybe a 15-16A supply. You might want to consider having a spare as well if down time is not acceptable.
DC solenoids do not cause inrush currents, they are inductors and resist current flow. Remember "ELI the ICE man" Voltage leads current in an inductor. There is quite a big 'out rush' tho when the current source is turned off.

#### Bernard

Joined Aug 7, 2008
5,788
How much force does a key require ? The relay shown is really a pull type with spring return, the spring supplying the key pressure. A throw of 5 mm might be enough ?? @ less current. As an example: Miniature 12V Push- Type Solenoid, 300 mA @ US $, 10 for 2.50 each. Force not listed. I would look a little longer. #### Bernard Joined Aug 7, 2008 5,788 Some examples of push type solenoids; MH-25X50TL, & a really cheap one JF-0520B 12 or 24 V, US$ 1.50 - 1.68..
Can tunes be played with only 10 notes ? Maybe " Taps ".
A pull type could be used with a lever, which could also allow staggering solenoids to fit key spacing.

#### slatepipe

Joined Oct 2, 2017
23
hi again

i bought two of these solenoid things and even though it they are advertised as push type, it looks like they are actually pull type, like you mention, and the spring only serves to push them back out when the current is released. so i'm glad i only bought two. but i'm not completely sure, i'll have to wait until i get the PSU bought and then test them

the keys? they're actually buttons - it's a Hohner button accordion, very similar to this one : http://www.musiciansfriend.com/folk-traditional-instruments/hohner-corona-iii-adg-accordion. they take very little pressure to depress so i don't think force of the solenoid is going to be a problem

so again - thanks for all this advice i'll have another look for some more appropriate solenoids, including checking out the ones mentioned above.

#### Bernard

Joined Aug 7, 2008
5,788
If your solenoids look like the picture, then they are most likely push or pull. Note the acorn nut on the end where the leads come out, the nut would press against a key. Depending on how far a key needs to be depressed, prob. less than 10 mm, then the stroke of solenoid could be shortened to match key strike allowing less operating current. Remove nut , slip on a spacer , reattach nut. It would be handy if you had some low value resistors, 1 ohm,1W to add in series with test solenoid to see how much current is required for reliable key operation, or availability of a variable voltage power supply, 0-12 V.

#### slatepipe

Joined Oct 2, 2017
23
hi again and happy new year, i've been a bit quiet with this project for the last few months, as other things got in the way but i set it all up again yesterday to see about making more progress with it.

i am getting more confident with using the programming code to move the hoist in and out to move the accordion and to get the solenoids working to play the keys (although i have yet to set these up according to the advice given above).

the issue that i am asking for some help with now is how i would make the control box work with just one hoist as i don't need two.
at the moment the setup is :
- mains transformer gives 24v to the control box via 2 pin phoenix connector.
- Crestron unit controls this control box via phoenix relay output into the control box via 5 pin din
- both hoists receive power from this control box via 8 pin to 5 pin din cables

if i unplug one of the 5 pin din cables from the control box (ie i unplug one hoist) then the remaining hoist does not work. i think i want to fool the control box into thinking that there are still both hoists connected when in fact there is only one. i tested some of the holes in the 5 pin din cable last night and one combination gave an output of 26v so i assumed that was the one that was supplying the hoist with power so am i right in thinking that i need to somehow make the control box think that there is still a hoist there by using a jumper wire or something? or is it a bit more complicated than that? if not then what would i need to do?

apologies if i continue to ask maybe basic questions but i am a beginner at this but am enjoying learning as i go along

again, many thanks for any help

#### shortbus

Joined Sep 30, 2009
8,802
Hoist?? This is a new addition to your question. Maybe show a schematic or drawing of how the 'hoist' controls are wired, so we can help.