This question is primarily to Karin (I understand that she made similar work), but to anyone. In her diagram, did you use the M1/M2 to your H-bridge, or use DIR and PWM from a micro-controller?
I plan to use a G gauge locomotive; use a LocoFi™ module; drive a MD13S H-bridge; use a 24 volt, 15 amp track-power module; construct an intra-locomotive power supply for the MD13S.
All hints or ideas are appreciated!
***IMPORTANT***
If looking for conversion to large scale, we have a *NEW* dedicated thread here: LocoFi™ for Large Scales (DC and AC power)
Karin's post mentioned above can be referenced here: https://www.wifimodelrailroad.com/forum/g-scale/g-scale-design-concepts
Here's the schematic for DDLLHA in case someone wants to DIY interface to external H-bridge. Please note that MD13S in only an example.
Please see https://www.wifimodelrailroad.com/forum/installation/3w-4-ohm-speaker for further discussion on speakers. You may continue the discussion about speakers there to keep it all in one place.
I retrofitted my O scale Alco RS with a 4ohm 3w speaker, 1.125" x 1.5", and have plenty of sound. My speaker fits neatly facing downward mounted on the floor of the chassis using 4 bolts and nuts, under the shell. I cut an oblong hole in the bottom of the chassis floor the size of the speaker so the sound is not muffled by the chassis or body shell plus the sounds bounce off the track/roadbed.
I believe the MD13S will be an ideal H-bridge for interfacing a modified LocoFi™ module to a higher-amperage locomotive.
My only remaining, and undecided, point in my design is finding the best applicable speaker to install in the fuel-tank (the speaker housing) on a USA Trains GP7/9 locomotive. If I am fortunate, a simple (?used/junked) computer speaker may provide a useable speaker and/or amplifier.
I have received two MD13S modules and will be retrofitting a 2 rail and 3 rail high amp draw O-scale locomotive after LocoFi modifies existing LocoFi 2 boards. Will also install bridge rectifier in both locomotives to prevent any accidental current flow issue when operating on our club's layout. From what was learned in 2019 when trying to do this there should be no problem in getting high amp draw locomotives operational at a reasonable cost and ease of modification.
Virtually my exact plan; with the addition of capacitance on the DC side of the bridge rectifier for any dirty-track issues. Planning to add a sound-amplification module and a fuel-tank speaker.
Until a full-fledged LocoFi™ module for large scales is available, the following setup (applies to LocoFi™ 3 only) can be used for higher amp motors. It applies to any large scale (including G and O) as long as there is space to fit them all.
The DIR and PWM can be exposed for any module for an extra charge of $30 for DULLHB and $60 for DDLLHA. External components like the H-bridge module, bridge rectifier, etc. are not included (please leave us a "Note" during checkout if you would like us to the modification).
The "clean" DC power can be battery or even AC that had been rectified and filtered. Please note that MD13S is only an example. Any H-bridge that accepts DIR and PWM as inputs can be used instead.