Hi there,
I'm designing a super small Arduino project where space is ver limited (max diameter is 30mm). I'm looking to use this Solenoid - 5V (Small) - ROB-11015 - SparkFun Electronics solenoid with an Arduino. As stated across the web, these can't be powered directly by the Arduino.
My question is, how do I power the solenoid in such a tight space?
Thanks
Surface-mounted MOSFETs are pretty small.
It's all very well saying you have 30 mm but how much is already taken up by other components?
Thanks Nick. I'm limited by the width of a tube (30mm). The tubes quite long so other components will fit inside.
Something like this? http://www.ebay.co.uk/itm/SMD-MOSFET-Driver-for-Arduino-AVR-PIC-Microcontroller-Reprap-Projects-/171027857973?
One last thing, to feed power into the MOSFET, would something like this work?:
http://www.brchobbies.co.uk/catalog/product_info.php?products_id=821
Thanks again
I don't quite see the connection. Perhaps if you gave more details about your project.
Sure. So basically its a small lock. A solenoid moves a pin in/out depending on a sensor connected to an Arduino Mini. The Arduino and sensor has a small Li-ion battery powering it, but I'm a little lost as to how to wirelessly power the solenoid (i.e. not through mains power).
S89:
Sure. So basically its a small lock. A solenoid moves a pin in/out depending on a sensor connected to an Arduino Mini. The Arduino and sensor has a small Li-ion battery powering it, but I'm a little lost as to how to wirelessly power the solenoid (i.e. not through mains power).
There is no practical way to send power for the solenoid 'wirelessly'. Your choices are either mains powered DC supply, battery power, solar panel, nuclear reactor, etc.
Lefty
Yeah sorry, wirelessly was the wrong word. Untethered or portable - so yes, a battery.
Hello,
I have been trying to recreate the circuit from the above post exactly. I have all of the components and have assembled them to what I believe to be correct. I do not wish to try it with my Arduino yet on the off chance that I destroy it, I would like to ask for a little more information before I continue. The area where I am slightly confused is the connections from the Mosfet, firstly I would like to confirm that the gate part of the circuit enters the Mosfet on the lowest of the three connections on the diagram that Nick kindly supplied. If that is the case then would anyone please be able to elaborate (possibly with the aid of a picture rather a diagram) on the relationship between the connection labeled 'source' (which as I understand it enters the Mosfet at the middle of the three connections) and the connection immediately below it that is lined up with (spacialy) and possibly connected to what I understand to be the gate connection on the Mosfet.
Thank you for your time.
radiopeck:
Hello,I have been trying to recreate the circuit from the above post exactly. I have all of the components and have assembled them to what I believe to be correct. I do not wish to try it with my Arduino yet on the off chance that I destroy it, I would like to ask for a little more information before I continue. The area where I am slightly confused is the connections from the Mosfet, firstly I would like to confirm that the gate part of the circuit enters the Mosfet on the lowest of the three connections on the diagram that Nick kindly supplied. If that is the case then would anyone please be able to elaborate (possibly with the aid of a picture rather a diagram) on the relationship between the connection labeled 'source' (which as I understand it enters the Mosfet at the middle of the three connections) and the connection immediately below it that is lined up with (spacialy) and possibly connected to what I understand to be the gate connection on the Mosfet.
Thank you for your time.
The question(s) you ask are best answered by reviewing the correct datasheet for your specific Mosfet. There will be a picture of the pin out of the transistor related to the specific device package style you are using.
Lefty
Thank you for the fast response. I have read the date sheet for my Mosfet (please see below) and I am clear of the order of connections of the three in a line. My data sheet also labels the top metal flange part of the Mosfet as being a drain connection, do I need to connect anything to that part?
I have attached an copy of the diagram supplied by Nick with a circle indicating the area of the diagram where I am most confused. Please could you have a look at this attachment and elaborate on the design somehow as at present I do not quite understand the circuit diagram.
Mosfet data sheet link:
http://www.proto-pic.co.uk/content/datasheets/N-CHannel-MOSFET60V30ADatasheet.pdf
radiopeck:
Thank you for the fast response. I have read the date sheet for my Mosfet (please see below) and I am clear of the order of connections of the three in a line. My data sheet also labels the top metal flange part of the Mosfet as being a drain connection, do I need to connect anything to that part?
Your free to use either drain connection or both just not neither.
I have attached an copy of the diagram supplied by Nick with a circle indicating the area of the diagram where I am most confused. Please could you have a look at this attachment and elaborate on the design somehow as at present I do not quite understand the circuit diagram.I think you are over thinking the picture/diagram. Or at least further explain your confusion over wiring up the source connection.
Mosfet data sheet link:
http://www.proto-pic.co.uk/content/datasheets/N-CHannel-MOSFET60V30ADatasheet.pdf
Am I right in thinking that the connection that I have circled, the one that goes into the gate terminal/connector (the bottom of the three connections on the right hand side of the Mosfet), also makes a connection with the wire labeled source? That is what it suggests to me however I would be more comfortable if you could confirm that for me as I don't want to risk damaging the ardunio.
You are over-thinking it. From your datasheet:
Ignore all the internal connections inside the MOSFET (upper-right diagram). Just connect up the three pins as shown on the schematic. R1/R2 junction goes to the gate pin. The load goes to drain, and the source goes to earth.
My data sheet also labels the top metal flange part of the Mosfet as being a drain connection, do I need to connect anything to that part?
No you don't. If you bolted it to a heat sink, you need to be aware that is the drain. So if the heat sink was earthed it would need to be bolted via an insulator.
radiopeck:
Am I right in thinking that the connection that I have circled, the one that goes into the gate terminal/connector (the bottom of the three connections on the right hand side of the Mosfet), also makes a connection with the wire labeled source? That is what it suggests to me however I would be more comfortable if you could confirm that for me as I don't want to risk trashing ardunio.
The wire you have circled does not connect to the gate. There is a gap.
Could you repeat the question? Are you asking if the circled pin is Source? Well it is labelled Source isn't it?
Ignore all the internal connections inside the MOSFET (upper-right diagram). Just connect up the three pins as shown on the schematic. R1/R2 junction goes to the gate pin. The load goes to drain, and the source goes to earth.
Pet peeve is the use of the work 'earth', often leading to newbies asking where to buy a arduino compatible ground rod to obtain a quality 'earth' connection. 
Ground or circuit ground or circuit common all are somewhat better words to use IMO as applied to arduino projects, however nothing is more confusing and misleading for beginners then the concept (of all the various application in different contexts) of the word ground.
I was very much assumed over several of the engineer cat fights over several decades at my refinery when talking about defining/designing/drawings/construction of the various grounding systems need for modern digital process control houses used in process control plants. This included multiple true ground rods installation and distribution, AC power grounds, personal safety ground, logic ground for distributive control system racks, common field ground connections from remote sensors and actuators, RS485 ground connections. It went on and on and there was no single engineer to define and enforce a common understanding and implementation of the ground requirements for all the subsystems and infrastructure equipment. You would think that the standards defined in NEC would have helped cut down on technical disagreement, but alas the NEC standards are not much better the bible in that different engineers (read priests ) could come up with large disagreements on how to implement properly.
Lefty
Ground or circuit ground or circuit common all are somewhat better words to use IMO as applied to arduino projects, ...
Graphic amended to clarify. 
