CSX Robert Mark R. Phoebe Vet .... Resisters are used to drop voltage, not diodes. .... Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. Diodes are voltage dropping components as there is a loss of 0.7 volts across the terminals of a diode. A string of ten diodes in series with the power lead to a component will drop the voltage by 7 volts. Mark. True, and often times diodes are a BETTER way to drop the voltage than resistors. For one, the voltage drop across a diode is fairly constant with variations in the amount current flowing through it, whereas the voltage drop across a resistor is directly porportional to the current flowing through it.
Mark R. Phoebe Vet .... Resisters are used to drop voltage, not diodes. .... Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. Diodes are voltage dropping components as there is a loss of 0.7 volts across the terminals of a diode. A string of ten diodes in series with the power lead to a component will drop the voltage by 7 volts. Mark.
Phoebe Vet .... Resisters are used to drop voltage, not diodes. ....
.... Resisters are used to drop voltage, not diodes. ....
Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits.
Diodes are voltage dropping components as there is a loss of 0.7 volts across the terminals of a diode. A string of ten diodes in series with the power lead to a component will drop the voltage by 7 volts.
Mark.
True, and often times diodes are a BETTER way to drop the voltage than resistors. For one, the voltage drop across a diode is fairly constant with variations in the amount current flowing through it, whereas the voltage drop across a resistor is directly porportional to the current flowing through it.
Exactly why diodes are used in 1.5 volt constant lighting circuits, and not resistors ....
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
I cannot recall the last time that a simple question such as the one that I asked the OP caused so much hoopla on a thread.
Is you layout DC or DCC?
I only asked the question because it was not clear if he was running his layout in DC or DCC.
True, he didn't ask if he could power the lights on the track bus, but he did write, "Thank you for any help that you can give me in this matter as it will be greatly appreciated". With so few lights to draw power, using the DCC track bus is a viable option. So, why not mention this option? He acknowledged that he has limited electrical expertise so he probably wasn't even aware of it.
Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime.
Rich
Alton Junction
richhotrainGive a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime. Rich
What we found out at work is, giving answers without the proper questions, was a disaster. We are taught to coach, aka teach in addition to providing an answer. So this old saying still is very true, even in today’s high tech world.
Per the wall wart solution, there are some negatives with using one. No circuit protection is one. The first time it shorts, kiss it good bye. So now we must or SHOULD add a fuse slightly below the rated current output.
Also, no on/off switch is provided, so when night becomes day, you pull the plug or add another switch. Two supplies mean 2 separate lighting buses, 2 circuit breakers and 2 on/off switches.
The throttle solution has build in circuit protection and a on/off switch, if these things are important to you. Per the concern of accidentally moving the throttle, a simple piece of 3M D/S tape and a plastic block will make a nice throttle stop.
Simplicity can be a relative term.
Jim
Once again I want to thank everyone who took the time to help me on this issue. I don't want to cause any trouble with my following comment, but in my original post I mentioned my limited electrical knowledge, but some of the replies were difficult to under stand, the item I had no clue as to what anyone was talking about was the term, " WALL WART " I actually thought people were referring to WALMART for some reason, it wasn't until the last few posts did someone actually explained what a WALL WART was, until then I had no clue. A Wall Wart definately seems to be the solution to my orginal post. I am at fault for not asking what a Wall Wart was, but I was so confused at that point I didn't want to cause any more confusion. Once again Thanks for all the help.
The great part is of all the possible solutions, every single one will work. Add the lights to the DCC buss, Wal warts, PC supplies, throttles and accessory terminals, reducing the current with resistors.
And they all have advantages and disadvantages.
In your defense, woodman, your original question was, could you use your Bachmann power pack to power your Atlas street lights. And the first reply said, yes, you could.
And now that you have that second Bachmann power pack, you can use that power pack to power your Walthers street lights. No need to even purchase a wall wart.
Incidentally, you can buy a wall wart at Walmart !
Mark R. CSX Robert Mark R. Phoebe Vet .... Resisters are used to drop voltage, not diodes. .... Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. Diodes are voltage dropping components as there is a loss of 0.7 volts across the terminals of a diode. A string of ten diodes in series with the power lead to a component will drop the voltage by 7 volts. Mark. True, and often times diodes are a BETTER way to drop the voltage than resistors. For one, the voltage drop across a diode is fairly constant with variations in the amount current flowing through it, whereas the voltage drop across a resistor is directly porportional to the current flowing through it. Exactly why diodes are used in 1.5 volt constant lighting circuits, and not resistors .... Mark.
Soo Line fan The great part is of all the possible solutions, every single one will work. Add the lights to the DCC buss, Wal warts, PC supplies, throttles and accessory terminals, reducing the current with resistors. And they all have advantages and disadvantages.
And let's not forget that a lot of forum members and visitors follow these threads, so the replies often prove helpful to others in addition to the OP of a thread. That's why it is helpful and informative to point out alternative solutions.
Just joined this forum after searching for lighting a walters street light. I purchased one then noticed it was 12V. We currently have a 19V AC bus and a 16V DC bus wired using a MRC DC power pack. (Yes I could reduce the DC output using the dial but there is a 5 year old around so guaranteed to fail). There are now 3 bus lines including the DCC bus. Looking through this forum I did not see the resitor required to drop the voltage to 12V from the 16V DC bus. I do not want to wire another bus for 12V DC as the lights are wired through a double throw switch one for AC and one for DC. Missing on the Walters box is the amperage rating for the lamps. Maybe the best thing is to chuck the lamp in the garbage but Walter's does make some nice looking lamps so that would be a shame. So maybe I could ask if someone has done this to provide the wattage and resitance of the resitor used. Also maybe a NMRA standard could be thought about given the great job with DCC.
kamtrain(Yes I could reduce the DC output using the dial but there is a 5 year old around so guaranteed to fail).
Soo Line fan. Per the concern of accidentally moving the throttle, a simple piece of 3M D/S tape and a plastic block will make a nice throttle stop
Also, you could remove the throttle dial from the pack.