---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 12/24/10: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:49 AM - Re: Avionics Installation Data Archives (Robert L. Nuckolls, III) 2. 02:07 PM - Alternator output voltage vs usable voltage at the bus (Neil Clayton) 3. 03:36 PM - Re: Alternator output voltage vs usable voltage at the bus (Richard E. Tasker) 4. 04:40 PM - Re: Alternator output voltage vs usable voltage at the bus (Kelly McMullen) 5. 09:17 PM - Off Topic - Looking for geared AC motor (jerb) 6. 09:41 PM - Off Topic - Looking for geared AC motor (jerb) ________________________________ Message 1 _____________________________________ Time: 05:49:43 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Avionics Installation Data Archives At 01:08 AM 12/24/2010, you wrote: > >No ftp access tp a server. I will send a cd to yoy. I need an address to >send it to. Thanks P.O. Box 130, Medicine Lodge, KS 67104 Thank you! Bob . . . ________________________________ Message 2 _____________________________________ Time: 02:07:26 PM PST US From: Neil Clayton Subject: AeroElectric-List: Alternator output voltage vs usable voltage at the bus Is my reasoning correct here? On my pusher, the internally regulated alternator puts about 13+ volts on the bus behind the panel. If there is 10 feet of #6 wire between the alternator and the battery (alternator, all the way forward to the 40A panel breaker, then to the bus). 10 feet of #6 wire at 0.004 mOhms/foot pulling 15 amps of current would see a voltage drop of 10 x 0.004 x 15 = 0.6 volt drop. Add a few more losses along the route and 13v is a reasonable expectation at the bus. So if the electrons start out their journey from the alternator at 14 volts, I'd see about 13.0 volts on the bus. Furthermore, if I externally regulated the alternator using +14 bus voltage as the target voltage, the regulator would compensate for the line voltage drop, and I'd see 14+ volts at the bus? Right, or is this Mech Engineer counting electrons wrong? Thanks Neil ________________________________ Message 3 _____________________________________ Time: 03:36:25 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Alternator output voltage vs usable voltage at the bus You are correct. Dick Tasker Neil Clayton wrote: > Is my reasoning correct here? > > On my pusher, the _internally_ regulated alternator puts about 13+ > volts on the bus behind the panel. > If there is 10 feet of #6 wire between the alternator and the battery > (alternator, all the way forward to the 40A panel breaker, then to the > bus). > > 10 feet of #6 wire at 0.004 mOhms/foot pulling 15 amps of current > would see a voltage drop of 10 x 0.004 x 15 = 0.6 volt drop. Add a few > more losses along the route and 13v is a reasonable expectation at the > bus. So if the electrons start out their journey from the alternator > at 14 volts, I'd see about 13.0 volts on the bus. > > Furthermore, if I _externally_ regulated the alternator using +14 bus > voltage as the target voltage, the regulator would compensate for the > line voltage drop, and I'd see 14+ volts at the bus? > > Right, or is this Mech Engineer counting electrons wrong? > > Thanks > Neil > > * > > * -- 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 4 _____________________________________ Time: 04:40:40 PM PST US From: Kelly McMullen Subject: Re: AeroElectric-List: Alternator output voltage vs usable voltage at the bus Your reasoning is correct, but the goal is not. You want 14V +/- 0.2 at the battery when you have enough rpm for significant positive output from the alternator. Your avionics and most everything else electrical will function fine at 12 to 14 V and are not that picky. Voltage is set to fully recharge the battery, so you have maximum endurance time available if the charging system quits. The rest of the electrical system doesn't care that much once the minimum voltage is present. So the cable size(s) from the alternator to the battery via the regulator and any resistance induced at connections are what matters. On 12/24/2010 3:03 PM, Neil Clayton wrote: > Is my reasoning correct here? > > On my pusher, the _internally_ regulated alternator puts about 13+ > volts on the bus behind the panel. > If there is 10 feet of #6 wire between the alternator and the battery > (alternator, all the way forward to the 40A panel breaker, then to the > bus). > > 10 feet of #6 wire at 0.004 mOhms/foot pulling 15 amps of current > would see a voltage drop of 10 x 0.004 x 15 = 0.6 volt drop. Add a few > more losses along the route and 13v is a reasonable expectation at the > bus. So if the electrons start out their journey from the alternator > at 14 volts, I'd see about 13.0 volts on the bus. > > Furthermore, if I _externally_ regulated the alternator using +14 bus > voltage as the target voltage, the regulator would compensate for the > line voltage drop, and I'd see 14+ volts at the bus? > > Right, or is this Mech Engineer counting electrons wrong? > > Thanks > Neil > > * > > * ________________________________ Message 5 _____________________________________ Time: 09:17:03 PM PST US From: jerb Subject: AeroElectric-List: Off Topic - Looking for geared AC motor Hey folks there are a lot of resources on these list. Anyone have or know of a source for an surplus (cheap is good) geared down 120V AC motor of 1/4-1/3 HP. Inline or right angle gear box will work - need a shaft output of around 20-43 (desired) or 80-100 RPM. This in not for an aviation orientated project. I can't justify the cost of a new unit for its intended use. If so please email direct. Thanks, jerryb ________________________________ Message 6 _____________________________________ Time: 09:41:20 PM PST US From: jerb Subject: AeroElectric-List: Off Topic - Looking for geared AC motor Hey folks there are a lot of resources on these list. Anyone have or know of a source for an surplus (cheap is good) geared down 120V AC motor of 1/4-1/3 HP. Inline or right angle gear box will work - need a shaft output of around 20-43 (desired) or 80-100 RPM. This in not for an aviation orientated project. I can't justify the cost of a new unit for its intended use. If so please email direct. 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