Your other option is a boost switch mode supply with voltage and current feedback.
https://www.edaboard.com/showthread...nt-Regulator&p=1555428&viewfull=1#post1555428
------------
If your 6V supply is capable of delivering 25AMPS - that is 150 Watts
Power = Volts X Current
if you boost the said voltage to 12V, assuming 100% efficiency! the current available will only be 12.5AMPS.
In practice it is possible to get a voltage converter of ~95% efficient at a specified load,$$$, though more common efficiency would be 50-60% for less $
-------
LM358 is a rather poor switch mode driver due to it's slow slew rate of 0.5 V/us. The best way to overcome it's limitations (if you can't afford a real switch mode controller or faster OP like TL084) is to reduce the switching frequency and increase the inductance respectively. Simply design it for continuous conduction mode with moderate (30 to 50%) current ripple. To avoid excessive capacitances, transistor and diode shouldn't be oversized.
--------
That just makes thing more complicated. The solenoid IS the relay that connects the starter across the battery. If the ignition switch was to do it alone, it would be far too big and need the heavy cables fed all the way to the dashboard. The switch connects 12V to the solenoid coil which creates the magnetic field to pull the heavy duty starter motor switch. You gain nothing by adding more relays in a chain.The next thing I am going to do (try) is remove the circuit from the ignition switch and create a separate relay for the starter solenoid. Just to see what that does for cranking first before trying to supplement the actual electric motor part with a boost
.....the only electronic component that can do that is a capacitor but if you think a bigger battery is expensive wait 'til you see the costs of 12V 'thousands of Farads' capacitors in comparison.
That just makes thing more complicated. The solenoid IS the relay that connects the starter across the battery. If the ignition switch was to do it alone, it would be far too big and need the heavy cables fed all the way to the dashboard. The switch connects 12V to the solenoid coil which creates the magnetic field to pull the heavy duty starter motor switch. You gain nothing by adding more relays in a chain.
Brian.
You are confusing the current paths. Cranking speed is decided by the power available to turn the starter motor and the load imposed on it by the engine. It has nothing whatsoever to do with the solenoid or ignition switch. The solenoid IS the relay, mounted near the battery and starter motor to reduce losses in the wiring while passing large currents. The solenoid coil is low power and can therefore be powered via the ignition switch along less cumbersome cables. The current along the battery-solenoid-starter motor-battery path is quite independent of the ignition switch so there is no point in trying to improve it.I have no doubt that adding a dedicated relay to supply current for starter solenoid (Which suggested is also a relay) will alleviate the pain experienced by factory ignition switch internals, and it may have a positive influence on cranking speed but that waits to be tested.
You are confusing the current paths. Cranking speed is decided by the power available to turn the starter motor and the load imposed on it by the engine. It has nothing whatsoever to do with the solenoid or ignition switch. The solenoid IS the relay, mounted near the battery and starter motor to reduce losses in the wiring while passing large currents. The solenoid coil is low power and can therefore be powered via the ignition switch along less cumbersome cables. The current along the battery-solenoid-starter motor-battery path is quite independent of the ignition switch so there is no point in trying to improve it.
If you want instant sure-fire starting I would look for solutions elsewhere, maybe pre-heating and/or pressurizing the fuel supply so it is available for instant use in the cylinders to lessen the time it takes to reach them.
Brian.
Probably a vehicle so heavily modified along with a starter motor solenoid that draws more current than the ignition switch is rated for.Burned out ignition switches is almost unheard of. What model of car is this?
Brian.
Failure to start at first engine rotation is probably more to do with fuel reaching the cylinders than cranking power.
Probably enough to crank over a 2 stroke manual lawn mower engine18Ah battery is inadequate for cranking truck engines.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?