Shop OBEX P1 Docs P2 Docs Learn Events
Solenoid — Parallax Forums

Solenoid

addaadda Posts: 13
edited 2006-12-20 23:28 in BASIC Stamp
Can anyone recommend a Solenoid(manuf/part#) to be controlled by a BS2 and 9V power?· A wiring diagram would also be appreciated (if other parts are required).· Thanks.

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-12-13 20:38
    Adda,
    ·
    ·· I can help with the schematic for the connections…These are for a relay, but electrically it’s the same.· As for picking the solenoid, nobody could recommend one because these devices are almost always application dependant.· There are continuous and pulse versions.· There are push and pull types.· Some even work both ways.· There are different amounts of force they handle as well as travel distance.· That is something you will need to look up from a distributor such as Digi-Key or Jameco.


    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    Driver_Relay_MOSFET.JPG
    320 x 240 - 6K
    Driver_Relay_NPN.JPG
    320 x 240 - 6K
  • addaadda Posts: 13
    edited 2006-12-13 22:28
    Chris,

    Thanks for your reply. Focusing on the mosfet diagram. I'm considering the following parts
    1. Mosfet http://www.parallax.com/search_results.asp?txtsearchParamTxt=mosfet&txtsearchParamCat=ALL&txtsearchParamType=ALL&iLevel=1&txtsearchParamMan=ALL&txtsearchParamVen=ALL&txtFromSearch=fromSearch
    2. http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=527&M=F0492A (12V version, pull type, int duty)

    a. I assume that we need to power the BS2 with 12v rather than 9V for this solenoid, correct?
    b. Is the above "parallax" mosfet correct for this solenoid?
    c. I'm somewhat confused by the resistance spec for the solenoid at 12V with int. duty - what does this require?

    Thanks.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-12-13 22:57
    Adda,
    ·
    ·· The driver (MOSFET/Transistor) you use must be rated for the device you’re driving.· In the case of the MOSFET I listed an IRL520 because it can handle most loads (up to 9+A).· In the case of the transistor though you have to choose that based on the load you’re driving.· This is another reason you need to choose the solenoid first.
    ·
    ·· As for powering the BS2, if your input power is 12V or less you can feed it to VIN and power the BASIC Stamp that way.· It is not recommend to power the BASIC Stamp Module from the same power supply as a Solenoid but using VIN you may be okay if you have adequate filtering on the supply.
    ·
    ·· The rating for the solenoid resistance could change depending on some factors, but the coil resistance will determine the current it draws at a given voltage, so knowing that will help you determine the current draw.· I hope this helps.· Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
  • addaadda Posts: 13
    edited 2006-12-20 14:06
    Chris,

    Thanks for the suggestion. I've selected a 12V, 50W Solenoid and the IRL520.

    Can I use a 12V 60W switching power supply and plug it directly into the BOE and power the Solenoid from VIN? I note your response above, my concern is with the power supply at 60W-do I need to take any precautions?

    Thanks.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-12-20 15:15
    Adda,
    ·
    ·· In theory you could, but I wouldn’t recommend it.· The BOE is primarily a breadboard platform and running 4+ amps of current through it wouldn’t be something I would recommend.· All you need is a common ground.· If you really want to use that same supply and have a good physical connection I would recommend using a Super Carrier Board where you could solder the high-current connections on the Proto area.· The regulator on that board would also be better for the BASIC Stamp since that board runs the Module from VDD rather than VIN.· I hope this helps.· Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
  • FireHelixFireHelix Posts: 42
    edited 2006-12-20 23:05
    I heard / read somewhere that with a solenoid, you should have a diode between it and the transistor to protect the transistor. I read that when the solenoid switches, it makes a reverse current that could damage the transistor. is that what the diode across the relay leads does? or would one inline between the solenoid (or relay) and the transistor prevent transistor damage? or am I just completely off and confused?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    I know just enough to tinker with something... but not enough to fix it when I break it. Thank the techie gods theres forums...
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-12-20 23:28
    FireHelix,
    ·
    ·· The diode in the schematics above serves that very purpose.· Take care.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
Sign In or Register to comment.