---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 09/26/10: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:09 AM - Re: Troubleshooting a Rotax generator (user9253) 2. 02:51 PM - Gem Sensor Optical Switch wiring (jonlaury) 3. 03:19 PM - Re: Gem Sensor Optical Switch wiring (jonlaury) 4. 04:40 PM - Re: Gem Sensor Optical Switch wiring (Richard E. Tasker) 5. 04:47 PM - Re: Re: Gem Sensor Optical Switch wiring (Daniel Hooper) ________________________________ Message 1 _____________________________________ Time: 07:09:14 AM PST US Subject: AeroElectric-List: Re: Troubleshooting a Rotax generator From: "user9253" Dan, How did you notice a generator failure? Was the low voltage warning light on? Did you verify low voltage with a voltmeter? The low-voltage warning light could be lying. My Rotax Heavy Maintenance Manual gives the resistance of the generator windings on page 64. With the master switch on and the engine off, remove the connector from the voltage regulator and check the resistance of the two generator yellow wires to ground. There should be infinite resistance to ground. Then measure the resistance between the two yellow generator wires. It should be less than one ohm. If more than one ohm, the relay contacts or generator winding is open. If the resistance checks are normal, chances are that the generator is OK. You could also do an operational check. With the voltage regulator connector still unplugged, connect a voltmeter and a high wattage lamp to the two yellow generator wires and start the engine. The lamp should get brighter and the voltage should go up with RPM. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=313775#313775 ________________________________ Message 2 _____________________________________ Time: 02:51:22 PM PST US Subject: AeroElectric-List: Gem Sensor Optical Switch wiring From: "jonlaury" The diagram for wiring this switch to an inductive load (relay coil) doesn't compute for me. Can someone explain why there's two voltage sources shown? The optical switch (40ma) in my fuel line is being used to drive a pump relay (coil @ 36ma) Thanks, J Read this topic online here: http://forums.matronics.com/viewtopic.php?p=313800#313800 ________________________________ Message 3 _____________________________________ Time: 03:19:05 PM PST US Subject: AeroElectric-List: Re: Gem Sensor Optical Switch wiring From: "jonlaury" Forgot the attachment. Here it is. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=313803#313803 Attachments: http://forums.matronics.com//files/els_900_wiring_144.pdf ________________________________ Message 4 _____________________________________ Time: 04:40:03 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Gem Sensor Optical Switch wiring I would guess that they show the two sources because one is labeled 5 or 12 VDC (to power the sensor) and the other is unlabeled. If you have the 12V version of the sensor, just connect the "+" of both supplies together. Basically take the top schematic showing a resistor load and substitute the relay and diode from the lower schematic for the resistor and you have it. Dick Tasker jonlaury wrote: > --> AeroElectric-List message posted by: "jonlaury" > > The diagram for wiring this switch to an inductive load (relay coil) doesn't compute for me. Can someone explain why there's two voltage sources shown? > > The optical switch (40ma) in my fuel line is being used to drive a pump relay (coil @ 36ma) > > Thanks, > J > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=313800#313800 > > > -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 5 _____________________________________ Time: 04:47:13 PM PST US Subject: Re: AeroElectric-List: Re: Gem Sensor Optical Switch wiring From: Daniel Hooper Hmm. Can I express my dislike for ambiguous datasheets here? Ok, now that that's done.. It may be expressing the fact that the blue wire, the optical receiver, does not care too much what its excitation voltage is. That is, even if you have a 5v or 12v part number, the voltage that drives the blue wire can be a wide range of values as long as it doesn't exceed 40mA if Blue is shorted to ground, as it will be when the sensor is triggered. The datasheet warns you not to connect the Blue wire to voltage without a limiting load (some sort of resistor, whether it's a relay coil (as in the figure 'Relay Output'), or the pull-up resistor R (as in 'CMOS/TTL Output'), but as long as you do that, you can use either the 5/12v source or some other voltage source. For your case, it sounds like a configuration like the figure 'External Load' might be the right way to do it, as long as there is a suppression diode in the coil. This advice isn't authoritative, since I've never worked with a sensor exactly like this before, but just a guess (hopefully a good one) based on experience. --Daniel On Sep 26, 2010, at 5:13 PM, jonlaury wrote: > > Forgot the attachment. Here it is. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=313803#313803 > > > > > Attachments: > > http://forums.matronics.com//files/els_900_wiring_144.pdf > > > > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.