AC generator/alternator lead acid battery charger RS1105 replacement - Page 1
Forum section: electronics / projects

author: strawberry
author_rank: Super Contributor
timestamp: July 13, 2017, 03:33:25 pm
content: Window comparator LM393 that provide charge and stop charge command to main switch IRFP4310ZOVP/battery open on hysteresis on single comparator LM393Any thought on this schematic?Where to find RS1105 internal schematic ...?

author: floobydust
author_rank: Super Contributor
timestamp: July 14, 2017, 03:04:52 am
content: The charge controller looks like a solid-state version of the old relay, charge controllersThe circuit has high-speed drive to the MOSFET but is only on/off control? I keep looking for an oscillator.It's just always pulsing full charge power on/off and relying on the battery as the integrator.The RS1105 is a tractor alternator or PM gen voltage regulator? Kubota?

author: strawberry
author_rank: Super Contributor
timestamp: July 14, 2017, 08:12:58 am
content: I will change schematic to thyristor controlled rectifier insted of MOSFET. I think thyristors can be found in RS1105. I think it is not posible make it thyristor edge control regulator due to wide change of generator frequency.Yes,RS1105 is for two wire AC generator for Yanmar. Original regulator broke too easy. Generator shoud be designed to give constant current?

author: strawberry
author_rank: Super Contributor
timestamp: July 14, 2017, 11:00:18 am
content: New thyristor shematic

author: floobydust
author_rank: Super Contributor
timestamp: July 14, 2017, 08:56:39 pm
content: I looked at your circuit and put a couple similar PM generator (dynamo) regulator sch to look at. One might be a schematic for Kubota regulator.The quiescent current drain is high for LM317, LED and R9/R10 so battery will go dead unless you have a switch somewhere.600V 40A SCR's but 1N4148's for D1, D4, D11 too small.I think you are using pulse-drive for the SCR's but why Q1/Q2 to make an SCR?I would have a RC snubber across the stator coil and a TVS for the LM317 as +ve spikes can be quite high, for reliability.TL431 could be used too. Discrete circuit is probably OK.

author: strawberry
author_rank: Super Contributor
timestamp: July 16, 2017, 04:45:08 pm
content: Your first schematic from Kubota should be the same as Yanmar RS1105.I replaced voltage regulator LM317 with TLV431 and other IC for low power.Can really 40..Ah 12V battery drain due to 10mA load?Q1/Q2 are not SCR but constant current source.I measured 30V peak to peak voltage at no load/open PM generator terminals. Output voltage should be sinusoidal ,I think.

author: floobydust
author_rank: Super Contributor
timestamp: July 16, 2017, 06:53:22 pm
content: The quiescent power loss is too much for my liking. Most regulators are powered from IGN with only Vsense (R9) going to the battery.IC1 will constantly be trying to turn the SCR's on when the engine is off, and two LED's etc.A flooded lead-acid battery loses roughly 5%/month. For a 40Ahr battery this is about 3mA leakage, just sitting there. Adding 10mA to this, self-discharge is 22%/month. OK if the tractor is never in storage.BAT- going to the PCB mounting screws, I would not do that. I find traces melt due to high-current (starter motor or dynamo) and the two grounds (engine block and chassis/frame).I see you are into PCB layout, so I will stop harping

author: strawberry
author_rank: Super Contributor
timestamp: July 30, 2017, 06:34:35 pm
content: Reverse engineered original Yanmar RS-1105 , and all magic they got from 12V zener diode as voltage comparator

author: floobydust
author_rank: Super Contributor
timestamp: July 30, 2017, 08:26:31 pm
content: That circuit very similar to old discrete automotive alternator regulators.I think any -ve transient on BAT hits the SCR's, so I consider them the high failure component.I could not find SCR datasheets but they are probably too low voltage, and there is no surge protection or snubber.If I was to design one of these, I would go for reliability and not precision.

author: strawberry
author_rank: Super Contributor
timestamp: July 31, 2017, 03:34:08 pm
content: Yes it is old regulatorI think, too high SCR's control gate current can do fail SCR.I can not proof it because original SCR broke apart. Tested other components and found none of them failed.In original schematic gate drive transistor seems operate in constant/limiting current for SCR's gate. I upgraded it to temperature stable constant current source.

author: floobydust
author_rank: Super Contributor
timestamp: July 31, 2017, 05:46:13 pm
content: OK I still have the same beef that quiescent current drain is high.R5 1MEG is huge Q3 only 12uA of base drive yet Q1 is on all the time when the engine is not running. So you still have a 15mA drain on the battery which I don't like. I don't see R8 1MEG doing anything (sch might be wrong).Other Vreg circuits use switched IGN to power the SCR drive, and a really smart design could use the PM generator output instead of the battery for powering the regulator...I would keep in mind ISO 7637-2 for vehicle transients. The (12V) test values expect vehicle switching transients (test pulse 3a) -150V and inductive load switching (test pulse 1) -75V to -100V spikes. For positive spikes +100V (12V) at 0.2usec at 10kHz (test pulse 3b).SCRsTN4015H-6T600V 40A (for "Motorbike voltage regulator circuits") and the40HF100is a 1kV 40A stud--mount rectifier diode, seem like overkill.But the other parts are lower voltage and the weakest link.Q1 2N3906 40V, MUR115 is 1A 150PIV.I would use higher voltage for Q1 and the diodes. No point mixing 600V and 150V parts.

author: strawberry
author_rank: Super Contributor
timestamp: August 04, 2017, 09:00:11 am
content: Quiescent current is 3.5mA@12V15mA SCR gate drive is supplied from alternator and do not interact with battery.40HF100 is not correct but field effect rectifier diode FERD40H100 from ST

author: strawberry
author_rank: Super Contributor
timestamp: November 01, 2017, 09:59:13 am
content: Finished