Banner Ad 1

Electronic pneumatic valve

R/C Submarine modelers

Postby Feet Wet » Fri Sep 26, 2003 6:06 pm

Hello All,
During one of my many daily visits to Internet-Land I found interesting item on the Graupner web site,www.graupner.de
It is an electronic pneumatic valve, usable with all gases,can be set to function in two modes;on/off or proportionally.Plugs in DIRECTLY to the receiver.Price as quoted by Hobby Lobby is $122.00, bit steep ,but in this field, so what!
Jonathan Eno
Feet Wet
SubCommittee Member
 
Posts: 122
Joined: Wed Mar 26, 2003 8:20 pm

Postby Carcharadon » Sat Sep 27, 2003 10:55 pm

Go to a junk yard, buy a fuel injector cheap. They work.
User avatar
Carcharadon
Registered User
 
Posts: 300
Joined: Fri Feb 21, 2003 9:10 am
Location: Savannah GA

Postby Sub culture » Sun Sep 28, 2003 5:49 am

Also you can go to your local tyre fitters.

Give them the price of a drink, and they'll likely give you as many used Schraeder valves as you can carry.

Mate these to a cheap servo, and you have a cheap, reliable and reasonably proportional system to control any gas you can think of (not too high pressure mind).

No sense in spendign more than you need to.

Andy
'Why are you staring at an empty pond?'

Want to dive your boat in crystal clear water? Then you had better Dive-in- http://www.diveintomodelsubmarines.co.uk
User avatar
Sub culture
SubCommittee Member
 
Posts: 2853
Joined: Fri Feb 21, 2003 6:55 am
Location: London, UK

Postby smwarships » Sun Sep 28, 2003 4:13 pm

Hello All ,
I purchased a normally closed solenoid from McMaster-Carr
item # 7877 K55 , with shipping it cost me $21.87 and I
received it within 2 days of purchase . The only thing to
buy is 2 fittings for the unit , easy to hook up and control.
The fuel injector will heat up if held open for a long time .
, I tried to modify one for RC Sub use ......

Darle :D
User avatar
smwarships
Registered User
 
Posts: 105
Joined: Sat Feb 22, 2003 12:17 am
Location: Morning View,KY

Postby Carcharadon » Sun Sep 28, 2003 8:13 pm

A fuel injector operates on about 4 to 5 volts even less. I use a resistor to drop the voltage from 12 and it can stay on continuously without a problem. If the fuel injector is in water the water will cool it. How hot do you think it gets when it's running in an engine? I suspect the fuel injector can take a fair amount of heat. Never had any problems running a gas through the fuel injector even for extended times.
User avatar
Carcharadon
Registered User
 
Posts: 300
Joined: Fri Feb 21, 2003 9:10 am
Location: Savannah GA

Postby smwarships » Mon Sep 29, 2003 12:01 am

Well lets see , a car engine will get to be around 200 degrees
or more during operation . So I would say that the fuel injector
gets pretty hot and puts up with a lot of heat .

I am trying to do things to keep the heat down inside my boat
so if the item produces excess heat , it won't be in my boat .

I will be using 2-12 volt motors in my fleet boat , the motors
will be in their own water tight containers which are made of
metal . The motors will be in direct contact with one of the
walls of the containers so heat will be transferred to the
container , the surrounding water will cool the container
helping the motors to run cooler .
And since my motors will be outside the main WTC , I don't
have to worry about shaft seal leaks destroying my
electronics, not to mention that my electronics will run cooler
with the motors removed from the WTC ..........

:D
User avatar
smwarships
Registered User
 
Posts: 105
Joined: Sat Feb 22, 2003 12:17 am
Location: Morning View,KY

Postby Carcharadon » Mon Sep 29, 2003 6:32 am

Well this got me curious. So I went out to my submarine hooked it all up and then opened up the fuel injector and released gas for one minute. I held the fuel injector and since it was releasing gas the fuel injector actually got cold. So then I turned off the gas and kept the fuel injector open for one minute and could not feel any change in temperature. Now I will admit however that the resistor got hot. But I could have run the fuel injector off my 6-volt receiver battery. Since the resistor is in water as is the fuel injector overheating is not a concern. In fact just the opposite, I'm more concerned about the fuel injector freezing up. But I know this doesn't happen either because onetime I stuck the submarine nose first in the mud in about 15 ft. of water. The only way I could retrieve it was to follow the trail of bubbles down to the submarine otherwise it would have been lost. I kept the gas on for at least 10 minutes and it neither overheated nor froze. If you operate the fuel injector on 12 volts, it will work but it will heat up. If you use the resistor to drop the voltage of course the resistor will heat up but not the fuel injector. If this is a problem the resistor could be mounted anywhere, preferably in water. Or you could simply use a six-volt source or tap into a six-volt source.
User avatar
Carcharadon
Registered User
 
Posts: 300
Joined: Fri Feb 21, 2003 9:10 am
Location: Savannah GA

Postby KOEZE » Mon Sep 29, 2003 8:41 am

How many amps does the injector consume. Can you tell anything about the flow trough it, etc. This could be very interesting of for my sub.

(If the current is not too high) you might consider using a DC voltage converter 7805 or similar. These transform dc voltage with much less loss than a resistor thus giving you more running time. They also require much less cooling (if any). I use them in my BEC system to create 5 volts for my servo's and receiver from my 12 volt main battery.

EJK
You don't stop playing because you get older,
you get older because you stop playing.
User avatar
KOEZE
Registered User
 
Posts: 230
Joined: Thu May 22, 2003 5:55 am
Location: Leeuwarden, The Netherlands

Postby THH » Mon Sep 29, 2003 8:46 am

Hi Carcharadon,

do you have any pictures of your System...especially of the fuel injector?

THH
THH
Registered User
 
Posts: 15
Joined: Fri Mar 28, 2003 4:38 am

Postby Carcharadon » Mon Sep 29, 2003 9:39 am

Amps I think are low as best I can tell; I think FI runs directly off the cars computer so you don't want a lot of amps involved unless there is a relay (too slow). Ans is I don't know. Pictures, I'll see what I can do. The system I used started out as an "emergency ascent " system in which gas was simply released into the hull of the ship to bring it up. Then it evolved to where I had the gas released into a bladder. And then I had the bladder connected to a bilge pump to displace the gas and fill with water. So my sub was first a dynamic diver with an emergency ascent system and then with the addition of the bladder/bilge pump a combination of static and dynamic. Off topic -- I made a rudimentary voltage dropper with a power transistor and a resistor powering a 12-volt light bulb. I adjusted the resistance until the bulb was very dim. This dropped the voltage to about three/ four volts. I tapped off of this to supply power to the receiver. But eventually without a heat sink it worked for a while until my power transistor admitted more voltage and the receiver would glitch a lot. Your solid-state idea sounds interesting would like to know more about it.



Edited By Carcharadon on 1064843532
User avatar
Carcharadon
Registered User
 
Posts: 300
Joined: Fri Feb 21, 2003 9:10 am
Location: Savannah GA

Postby KOEZE » Mon Sep 29, 2003 10:44 am

[url=http://www1.int.conrad.com/scripts/wgate/zcop_in2a1d7ebb/~flNlc3Npb249UDkwX0NPUF9FTjpDX0FHQVRFMDI6MDAwMC4wMTJhLjE2N2JlYTZiJn5odHRwX2NvbnRlbnRfY2hhc
nNldD1pc28tODg1OS0xJn5TdGF0ZT00ODU4MzU0MjM=?~template=PCAT_AREA_S_BROWSE&glb_user_js=Y&shop=A_B2C_IN&p_init_ipc=X&~cookies=]Conrad Electronics homepage.[/url]

Try this link and ask your local electronics dealer for the parts. Should not be more than a couple of $.
Connect 12 volt to one pin, Connect ground to another pin and you'll get the voltage you want (determined by the part). Which voltage connects to which pin depends on which version or housing you buy. If nessecary (for BEC) you can add a couple of capacitors for voltage stabilisation.

If you intent to use a one amp regulator with a one amp consumer add a heatsink. I usually go a bit higher than what I expect to use. (My BEC system uses a 5 amp regulator which is more than I'll ever use but I want to be safe. It is bolted to the aluminum motorframe for cooling and barely heats up.

EJK
You don't stop playing because you get older,
you get older because you stop playing.
User avatar
KOEZE
Registered User
 
Posts: 230
Joined: Thu May 22, 2003 5:55 am
Location: Leeuwarden, The Netherlands

Postby smwarships » Tue Sep 30, 2003 8:28 pm

Hi Carcharadon,

What type of car did you get your fuel injector from ?
I tried one from a Dodge Caravan V6 , maybe that was
the problem that I had ? ???

Darle
User avatar
smwarships
Registered User
 
Posts: 105
Joined: Sat Feb 22, 2003 12:17 am
Location: Morning View,KY

Postby Carcharadon » Wed Oct 01, 2003 5:42 am

Ford throttle body fuel injection as best I can remember. If the operating voltage is unknown, I'd start with the lowest voltage that opens the FI.



Edited By Carcharadon on 1065001813
User avatar
Carcharadon
Registered User
 
Posts: 300
Joined: Fri Feb 21, 2003 9:10 am
Location: Savannah GA


Return to R/C Modeler

Who is online

Users browsing this forum: Google [Bot]