My Atlas twin coil machines are acting up lately, and the solution so far I found on the board is to use a capacitor discharge unit like the Circuitron's snapper. Before I commit to buy the device, I would like to know if it absolutely requires a 16V power supply, because currently I am using a 12V 2amp ps and I don't know if it will deliver sufficient juice to charge up the capacitor. Another question I have is the 470ohm resistors I used on the LED switch signals, do you think the 25v of momentary joult would fry the LED instantly, I want to avoid changing the resistors to each lead if possible, thanks for your help in advance.
Almost certainly the only drawback of using a 12V power supply would be that the power would be reduced. Meaning that you'd be able to throw fewer turnouts on the same route. How many turnouts you can throw depends on your switch machines. (What scale and type of Atlas machines are you using?) Did you read somewhere that the Snapper requires a 16V supply? The Circuitron catalog just says 25 volts or less. You could always buy the Snapper and see if using it with your 12V supply solves your problems. If it doesn't, then you can upgrade your power supply, as you probably not going to solve your problems without more voltage anyway. First of all, I think you should clarify how you have this wired up. Maybe it's just me, but I don't understand why you'd be using LEDs in series with the capacitor discharge unit. (Aren't your LEDs lit up for more than a fraction of a second?) If, instead, the LED circuits are in parallel to the turnout control (for example, if you're using something like the Atlas Snap Relay to control the LEDs) then the 25v would never be flowing through the LEDs themselves. (If the LEDs are indeed in series with the capacitor, then technically the answer to your question depends on the maximum current the LEDs are rated for. If you are using typical LEDs rated for no more than 5V and 30ma, then you would need a higher ohm resistor. But, if the LEDs are indeed in series with the capacitor, you should change things around so that isn't so. In fact, you should keep that 12V supply around to power the LEDs regardless.)
Isn't a farad a measure of power, in this case storage of power? Isn't the size of the capacitor the governing factor on how many switch machines it will throw at once? Voltage may play a role in how fast the capacitor recharges? I went to manual throws on the latest layout, so my knowledge of basic electrical laws went to ground zero.
A farad is a measure of capacitance which does involve storage of energy. However, the energy stored is directly related to the voltage across the capacitor. If you double the voltage you double the amount of energy stored. The charge rate is not dependent on the voltage but rather is controlled by any resistance in series with the capacitor. If you put a resistor and capacitor across a 10 volt power supply it will charge to the powers supply voltage in the same time that the same resistor and capacitor will charge to the maximum voltage when connected to a 20 volt supply.
How are the Atlas machines starting to act up? Could it be age, lack of maintenance, problems with the control buttons? How are your led's wired with relation to the switch machine wiring? The Snapper will work with input voltages from 12V to 25V. The unit comes with a current limiting resistor (different than your led resistors) which is recommended if you use a power supply of more than one amp. Not knowing how your led's are wired, would prevent you getting correct info on them. A benifit of the snapper is preventing the switch coils from burning up if a control button sticks.
My 1.5v LED signals are connected via Atlas Snap Relay with 470ohm resistor to counter the 12V of power. I don't understand why a 25v of output from the Snapper won't burn out the LED if 12v constantly power the LEDs. A lot of people suggested of using this device because their switch get stuck in the middle of throw and that is exactly what I have been experienced lately, I guess there is not enough juice to make a completely throw so the points are stuck in the middle causing derailments. I upgraded the power supply from 1 amp to 2 amp per my conversation with tech support from Altas but that didn't really help, thanks for your inputs in the matter thus far.
Your led's should not be powered by the snapper. The snapper only supplies power to the switch machine for a short duration and will not keep an led lit. The led's may even prevent the snapper from recharging between switch throws. You can use the snapper to power the snap relays in parallel with the switch machines but the led's should have their own power source. You can use the same power supply for the led's as well as the snapper but the output of the snapper (which is DC) must only be used for the switch machines and snap relays.
The Atlas Snap Relay uses one circuit (the coil, activated by your switch control) to switch two other circuits (at least one of which is your LEDs, if you've wired them correctly). Since it's a relay, by definition the current that throws the coil does not pass through the switched circuits. The coil and the switched circuits are mechanically linked but electrically separate. When you install the Snapper, you will connect it between the Atlas Snap relay coil and your switch control. The 25V from the Snapper will not pass through the part of relay that controls the LED circuits, only through the coil. Your LEDs can be connected in parallel to your 12V supply - or to a totally different supply, which is not a bad idea - and will not be affected by the Snapper. By the way, in the future you may want to look into Tortoise machines instead of snap relays and coil switch machines. Tortoises cost only a little more than the Snap Relays, provide the same switching features to control LEDs, and require less power to throw.
