OKR-T10 Regulator Wiring Shematic from Murata with Components Added

[Todd Mulske]

I pulled the actual wiring schematic off of Murata's Data Sheet for the OKR Standard Version remote on/off and placed my components into it. With this wiring no current ever goes to the momentary switch or to the master switch or through the voltage meter on/off switch. The potentiometer also never has any current flowing through it. I will be putting this together in the next week; I will have to order a NC momentary switch as all I have on hand are NO momentary switches.

Ok, now what do you all think.

 

[dreamerman]

can you kindly post some schematics? i'm planning to use OKR-T10 on my next mod. thanks

 

[Todd Mulske]

This is a schematic. It is the actual schematic provided on the datasheet with the components installed. I couldn't make it better than this. Manufacturer Schematic. If you have any questions about any part of the schematic; just ask, I would be happy to help.

 

[CapeCAD]

With the 10k resistor from on/off control to ground discussed before you can use a NO switch from on/off to vin. This is safer since a switch failure would turn the converter off.

 

[Todd Mulske]

I am going to try to explain this schematic the best that I can; I am sure some of the modders out there will not need this, but for those who have a hard time deciphering a wiring schematic it could be confusing. I am going to start with the positive side of the battery and then go to the negative side.

1. Vin Connection: There needs to be a 20 gauge wire soldered to the positive battery contact; the wire will then connect to a fuse-holder that will hold a 3-4 amps 12 volt fuse. The wire will go from the fuse holder to the Vin or voltage in of the converter.
2. Vout Connection: A 20 gauge wire will go from the Vout of the converter to the positive contact on the battery connector. Another 20 gauge wire will be spliced into this wire before the battery connector that will go to pin 2 or the positive terminal of the voltage meter (1s-6s) voltage meter. The positive side of the circuit is now complete.
3. Common or Ground: A 20 gauge wire needs to be soldered to the negative terminal of the battery contact; from there it will go to a on/off SPST switch. The other side of the SPST switch will then be coupled with a wire that goes to a NC Momentary Switch; the other side of the NC switch will go to the Control Pin of the converter. The ground will also be connected to the Ground of the converter, to one side of either a NO Momentary switch or a SPST on/off switch and the negative terminal (pin1) of the voltage meter will be connected to the other side of either of these switches; the ground will also be coupled with the negative side of the battery (atomizer) contact and with the potentiometer. The common or ground side of the circuit is now complete.
4. Trim off the Converter: The trim will have a 220 ohm .5% tolerance or better 1/10 watt 50 ppm or better resister wired to it. The The other side of the resistor will have a 20 gauge wire running to the potentiometer.
5. The entire circuit is now complete.

6. If you would like the voltage meter to come on when you press the switch and go off when you let go of it use a NO momentary switch; or if you want it to stay on until you push the switch again use a SPST on/off switch.
7. There must be a on/off SPDT switch off the negative side of the battery contact because even when you release the NC switch there will still be power to the converter through the ground pin and the Vin pin.
8. Why no pull down resistors. The control pin has a internal mofset built into it. When the control pin is open the converter internally powers up. The Vin goes to the control center of the converter and internally adjusts the voltage to turn the converter on when the control pin is opened. When the control pin is connected to ground the mofset shuts the converter down. That is why I used a NC switch between ground and the control pin; to close the circuit; turning the converter off; when you press the switch, the control pin is open and the converter powers up.
9. It is suggested that no external capacitors be connected to the converter. Page 9 of the material data sheet below:

Output Capacitive Load

These converters do not require external capacitance added to achieve rated
specifications. Users should only consider adding capacitance to reduce
switching noise and/or to handle spike current load steps. Install only enough
capacitance to achieve noise objectives. Excess external capacitance may
cause regulation problems, degraded transient response and possible oscillation
or instability.

10. One last note: Voltage should never be sent through the control pin. It will eventually damage it; why; because the vin goes into the control center and if voltage is sent to the control pin as well now there are two lines of current being sent to it causing potential damage to the control center and internal mofset. A pull down resistor should never be used between the control pin and ground because when the the control pin is closed the converter turns off. Placing a resistor between the control pin and ground will cause a floating effect in the control center because the control pin is not all the open or all the way closed because of the resistance that has been added.

 

[CapeCAD]

A few corrections:

8. Why no pull down resistors. The control pin has a internal mofset built into it. When the control pin is open the converter internally powers up. The Vin goes to the control center of the converter and internally adjusts the voltage to turn the converter on when the control pin is opened. When the control pin is connected to ground the mofset shuts the converter down. That is why I used a NC switch between ground and the control pin; to close the circuit; turning the converter off; when you press the switch, the control pin is open and the converter powers up.
.

Please see below, pull downs allow the use of a NO switch for safer use, a NC will work without a pull down resistor but switch failure will leave the converter on.

9. It is suggested that no external capacitors be connected to the converter. Page 9 of the material data sheet below:

Output Capacitive Load

These converters do not require external capacitance added to achieve rated
specifications. Users should only consider adding capacitance to reduce
switching noise and/or to handle spike current load steps. Install only enough
capacitance to achieve noise objectives. Excess external capacitance may
cause regulation problems, degraded transient response and possible oscillation
or instability.
.

This converter can drive external capacitive loads from 200uF to 1000uF depending on ESR value. Mods using long wires for connections could consider adding some external capacitance to improve performance.

10. One last note: Voltage should never be sent through the control pin. It will eventually damage it; why; because the vin goes into the control center and if voltage is sent to the control pin as well now there are two lines of current being sent to it causing potential damage to the control center and internal mofset. A pull down resistor should never be used between the control pin and ground because when the the control pin is closed the converter turns off. Placing a resistor between the control pin and ground will cause the a floating effect in the control center because the control pin is not all the open or all the way closed because of the resistance that has been added.

Please read the datasheet page 3 - remote on/off control and page 4 - note 5 to see that vin can be applied to the enable pin. The TI converter is limited in this way, but not the OKR.

Addition of the proper value pull down resistor will not harm the converter and will bring the pin to the proper turn off voltage.

 

[Todd Mulske]

Please see below, pull downs allow the use of a NO switch for safer use, a NC will work without a pull down resistor but switch failure will leave the converter on.

You are right if the contacts on a NC switch fails the converter would stay powered up or turned on. The chances of this happening with the switch are next to none because their is absolutely no voltage or current flowing to or from the switch.

This converter can drive external capacitive loads from 200uF to 1000uF depending on ESR value. Mods using long wires for connections could consider adding some external capacitance to improve performance.

I did not say that external capacitors would definitely harm the converter or cause problems with it. I just simply looked at the data sheet and it said capacitors should not be used for anything except to reduce noise in the signal. It also stated that there could be potential problems. This is a personal opinion issue as far as capacitors go, mine is to follow the advice of the manufacturer and not use them. I also spoke with a technician from Mouser Electronics about this and was told it would be best not to use them unless I had huge spikes and he told me that for my application capacitors would little to no benefit. I am going to try it without them and see how it works; if I have a problem I can always add them later.


Please read the datasheet page 3 - remote on/off control and page 4 - note 5 to see that vin can be applied to the enable pin. The TI converter is limited in this way, but not the OKR.

I did see that a voltage of 1.5 volts to Vin max could be used to turn the converter on on a standard version converter which I have. A pull down resistor was not mentioned for the standard version, but was mentioned for the E version converter.

Addition of the proper value pull down resistor will not harm the converter and will bring the pin to the proper turn off voltage.

This is another thing I talked to a tech about and he stated that by running power to the control pin and then using a pulldown resistor between control and ground you would be in a sense creating a partial short in the circuit.

I am the type person that looks at the manufacturer's specs and try to follow them as close as i possibly can. They are the ones who designed this converter, not me. People who have been making these mods with a pulldown resistor and capacitors are having success doing it this way so i am not criticizing them, just following specs as close as i can. I will say this, if I put everything together and notice huge spike current load steps, I will probably install a capacitor, but if not, I am not going to try to fix something that works.

Once again, you spent a lot of time helping me out with this project and I do appreciate it. I am grateful that you took time out of your day to give me a hand as well as one or two other members on the forum, Mamu being one other person who helped me out.

A few corrections: