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Retro Hawk peak amp draw


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#1 CDavis7

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Posted 14 June 2019 - 01:39 PM

Has anyone ever tested how many amps an RH motor draws the instant full power is drawn?

I know theyre low amp motors but Im wondering how much headroom they need
Chris Davis
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#2 Racer36

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Posted 14 June 2019 - 01:54 PM

Not very scientific , but I saw between 5 and 6 amps on the power supply on a friends track . One RH powered flexi when the power came on.

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#3 Don Weaver

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Posted 14 June 2019 - 04:12 PM

Doubt slot racers have an instrument that responds quick enough to record inrush current at start.  Not sure about these type of motors but 7 to 8 times nameplate current is a common estimate.


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#4 havlicek

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Posted 14 June 2019 - 04:18 PM

Doubt slot racers have an instrument that responds quick enough to record inrush current at start.  Not sure about these type of motors but 7 to 8 times nameplate current is a common estimate.

 

Yep...and to confuse things even further, the current draw will be affected significantly by the load the motor is under.  Different gearing, chassis will make the same motor draw different amounts of current.


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#5 CDavis7

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Posted 14 June 2019 - 05:28 PM

Thanks to everyone who commented so far. This is for a project Im working on.

Most power supplies are designed with fail safe circuitry which limits how much current a motor can draw at startup. I need to know how many amps a battery should have to not starve a motor of current at startup.
Chris Davis
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#6 CDavis7

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Posted 14 June 2019 - 05:31 PM

I might just put a big cap in my circuit instead. 🤔
Chris Davis
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#7 NSwanberg

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Posted Yesterday, 01:01 AM

Has anybody ever used an amp recording strip chart for the amp draw of a slot car running several laps at speed? It might tell a lot about what a power supply can actually deliver.


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#8 Ramcatlarry

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Posted Yesterday, 11:28 AM

I tested track wiring with a 'clamping amp meter' which can display and hold peak info digitally.  That kind of meter can lock on a nanosecond of draw.  Group-7 and euro class motors can show over 40 amps EACH.  Problem is that data is really meaningless.  Maximum amps is when the armature wire smokes.

 

A typical commercial rental/flexi track should have about 10 amps PER LANE of power available in the power system - the transformer and wiring. Average braid is equal to a #12 ga wire as should the track.  If you regularly race faster stuff, the amps per lane should double, with the braid being the 'choke'.


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#9 zipper

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Posted Yesterday, 12:42 PM

Group 7 cars draw average almost 40 amps - insane! Our power pack has an accurate digital meter.


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Pekka Sippola

#10 CDavis7

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Posted Today, 04:09 AM

I tested track wiring with a 'clamping amp meter' which can display and hold peak info digitally.  That kind of meter can lock on a nanosecond of draw.  Group-7 and euro class motors can show over 40 amps EACH.  Problem is that data is really meaningless.  Maximum amps is when the armature wire smokes.
 
A typical commercial rental/flexi track should have about 10 amps PER LANE of power available in the power system - the transformer and wiring. Average braid is equal to a #12 ga wire as should the track.  If you regularly race faster stuff, the amps per lane should double, with the braid being the 'choke'.


Thanks Larry. This is what I was looking for and its helpful.

Much appreciated
Chris Davis
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