Powering your Mount

[04Stefan07]

I am currently using an HEQ5 Pro and have it powered via my Pocket Powerbox Advanced. I have a few devices plugged into it and I get a max of 11.8V during my imaging sessions.

When slewing however it drops to 11.6V and that's when the mount's power light starts to flash. I have also noticed when imaging/guiding you can hear the mount make some noise and sometimes the power light will go off very quickly when it makes the noise and come back.

Would I be better off running dedicated power for my mount and not use the power box or should I be puchasing the "certified" power supply that Pegasus Astro recommends? I do have a spare power outlet at the telescope but in the end I am trying to reduce the amount of cabling and power packs needed for my setup.

Would the power supply they sell guarentee me 11.9 to 12V of steady power?

[Padraic M]

The Pocket Powerbox is a power controller but it can only control the power provided by the supply. if you're only getting 11.8V then your power supply isn't providing enough juice to the PPBA. You need to get a beefier supply - 5A or higher, and preferably 13.8V rather than 12V. The voltage will drop once you start to draw current, and the HEQ5 gets very edgy at around 11.5V.

You don't say what PSU you're using. Many of us use Nevada Radio supplies - either the 6-8A one or the 30A that I use. FLO supply both. The PPBA is perfectly capable if it's fed with enough power.

[04Stefan07]

55 minutes ago, Padraic M said:

The Pocket Powerbox is a power controller but it can only control the power provided by the supply. if you're only getting 11.8V then your power supply isn't providing enough juice to the PPBA. You need to get a beefier supply - 5A or higher, and preferably 13.8V rather than 12V. The voltage will drop once you start to draw current, and the HEQ5 gets very edgy at around 11.5V.

You don't say what PSU you're using. Many of us use Nevada Radio supplies - either the 6-8A one or the 30A that I use. FLO supply both. The PPBA is perfectly capable if it's fed with enough power.

Ah!

Yep, sorry. I am using this power supply.

https://www.jaycar.com.au/12v-dc-10a-desktop-power-supply-2-1mm-dc-plug/p/MP3241

[Padraic M]

Yeah there have been lots of problems with that type of generic power brick.  I have one myself 10A 12V but it gives similar results. You will need an upgrade! If you have a second one you could try powering the mount directly with it. 

[Ian McCallum]

Although we say 12V, most of the larger ones tend to be 13.8V.  This is perfectly acceptable for the job in hand.

I think the problem that you are experiencing with the voltage drop is probably due to the power supply.  It's probably struggling with the load on it or perhaps the cable feeding the mount simply is too thin for the job, thereby creating a bottleneck.  Does the power supply or cable get hot, when the mount is slewing?🤔

Edited April 16, 2022 by Ian McCallum

[malc-c]

The HEQ5 tends to be very voltage sensitive and doesn't tolerate low voltages well.  Running it form a 13.8v system works well.  

[04Stefan07]

Cable doesn't seem to get hot when slewing. Just not having consistent voltage throughout the imagine run.

[scotty38]

I thought my power was ok but I had odd issues now and then that all went away when I bought one of these:

https://www.firstlightoptics.com/power-accessories/nevada-psw-30-25-30a-switch-mode-power-supply.html

Might cost a few quid but in the grand scheme of astro gear it's not bad and it means I can now forget about power issues at least 🙂

[Ian McCallum]

8 hours ago, 04Stefan07 said:

Cable doesn't seem to get hot when slewing. Just not having consistent voltage throughout the imagine run.

Sounds like that the power supply isn't that well stabilised, as it seems to drop voltage whilst under load.🤔

[04Stefan07]

1 hour ago, Ian McCallum said:

Sounds like that the power supply isn't that well stabilised, as it seems to drop voltage whilst under load.🤔

The closest thing I can find down here is this one which looks like the Nevada one.

https://amateurradiosupplies.com.au/index.php/product/sadelta-sps-2530d-switching-power-supply/

Almost impossible to find them here!

[Padraic M]

Looks very similar alright but that's pricey! You'd almost be better getting it shipped.

[Toltec]

There is something a bit odd with the SW mounts and supply. If I run my AZ-EQ5 from a battery with a measured 12.4v at the mount input (12.6v at the battery) the handset says 11.8v. When I put a boost switching psu in line set to 13.5v the handset reads 13.4v 

I'm wondering if they have an internal regulator, typically when you drive one of those below the set output voltage you lose a little voltage across it. I haven't bothered adjusting the output to see if that is the case though. 

[Physopto]

15 minutes ago, Toltec said:

There is something a bit odd with the SW mounts and supply. If I run my AZ-EQ5 from a battery with a measured 12.4v at the mount input (12.6v at the battery) the handset says 11.8v. When I put a boost switching psu in line set to 13.5v the handset reads 13.4v 

I'm wondering if they have an internal regulator, typically when you drive one of those below the set output voltage you lose a little voltage across it. I haven't bothered adjusting the output to see if that is the case though. 

It is possible that the battery cannot supply enough current at the mount at 12.4 volts so the voltage drop internally on the mount. When you boost the voltage to 13.5 volts it may be the power supply can supply a greater current so the voltage does not drop as much.

It is the wattage that counts in the end. i.e. Total power ( wattage ) is the voltage times the current. The wiring CSA  and length,  has  a big effect on the power transmission.

[Ian McCallum]

Here's the one I use. It's a switch mode power supply, so it can produce a bit of radio frequency interference to my amateur radio transceiver. 

It's got variable voltage control and run at 25A continuous or 30A peak, which is overkill. 🙄

[Ian McCallum]

3 hours ago, 04Stefan07 said:

The closest thing I can find down here is this one which looks like the Nevada one.

https://amateurradiosupplies.com.au/index.php/product/sadelta-sps-2530d-switching-power-supply/

Almost impossible to find them here!

Something like this should do...  They do cost a fortune in Oz!😲

https://amateurradiosupplies.com.au/index.php/product/dirland-d-1206gs-regulated-power-supply/

Here's an equivalent one that I could buy in the UK, it cost £40 (around AUS$70).😲

https://www.kcb.co.uk/contents/en-uk/p55203_PS-08-6-8A-Linear-Power-Supply.html

Edited April 17, 2022 by Ian McCallum

[Toltec]

1 hour ago, Physopto said:

It is possible that the battery cannot supply enough current at the mount at 12.4 volts so the voltage drop internally on the mount. When you boost the voltage to 13.5 volts it may be the power supply can supply a greater current so the voltage does not drop as much.

It is the wattage that counts in the end. i.e. Total power ( wattage ) is the voltage times the current. The wiring CSA  and length,  has  a big effect on the power transmission.

The boost psu is running off the same battery and it doesn't pull the battery voltage down noticeably. It is just the small 7Ah SW power tank, with a new battery, it will run the mount for four hours and still be above 12v. 

Im going to have to test the mount handset reading at various input voltages now

Edit:

The handset does read the input voltage correctly, within 0.1 at least which is within reading error. What I must have done is measure the voltage at the battery first then at the input after putting the boost psu on. Turns out the lead supplied with the power tank drops half a volt or more even without driving. I have another cable which was much better. The cable supplied with the mount is fine, very little drop on that. 

They do want over 12v though so a 12v psu with a not so good connection lead is not going to do the job. 

 

Edited April 17, 2022 by Toltec

[04Stefan07]

8 hours ago, Ian McCallum said:

Here's the one I use. It's a switch mode power supply, so it can produce a bit of radio frequency interference to my amateur radio transceiver. 

It's got variable voltage control and run at 25A continuous or 30A peak, which is overkill. 🙄

Can almost cook a chicken with that power 😛

[04Stefan07]

8 hours ago, Ian McCallum said:

Something like this should do...  They do cost a fortune in Oz!😲

https://amateurradiosupplies.com.au/index.php/product/dirland-d-1206gs-regulated-power-supply/

Here's an equivalent one that I could buy in the UK, it cost £40 (around AUS$70).😲

https://www.kcb.co.uk/contents/en-uk/p55203_PS-08-6-8A-Linear-Power-Supply.html

Yeah, we pay through the nose here with a lot of things.

Is there some sort of banana plug to 2.1mm DC adapter as well?

[Ian McCallum]

21 hours ago, 04Stefan07 said:

Can almost cook a chicken with that power 😛

It'll power a 100W HF amateur radio, no problem. 

[Ian McCallum]

21 hours ago, 04Stefan07 said:

Yeah, we pay through the nose here with a lot of things.

Is there some sort of banana plug to 2.1mm DC adapter as well?

I usually just make up a cable with banana plugs at one end and a DC barrel plug at the other. 

[bosun21]

On 17/04/2022 at 14:51, Toltec said:

There is something a bit odd with the SW mounts and supply. If I run my AZ-EQ5 from a battery with a measured 12.4v at the mount input (12.6v at the battery) the handset says 11.8v.

I have just bought the Nevada (8amp) for my EQ5 pro which immediately sorted my go to accuracy and the motors were running much smoother. With my mount sitting parked i checked the voltage on the handset and it also was reading 11.8v. When I checked the output of the Nevada it was 13.6v

[Toltec]

9 minutes ago, bosun21 said:

I have just bought the Nevada (8amp) for my EQ5 pro which immediately sorted my go to accuracy and the motors were running much smoother. With my mount sitting parked i checked the voltage on the handset and it also was reading 11.8v. When I checked the output of the Nevada it was 13.6v

Worth checking the cabling, as per my later post I found the car type plug to 5.5/2.1 plug cable was dropping a significant amount between the battery and mount cable. 

[bosun21]

1 minute ago, Toltec said:

Worth checking the cabling, as per my later post I found the car type plug to 5.5/2.1 plug cable was dropping a significant amount between the battery and mount cable. 

I will swap my cable over to the ring tongue connection and check the voltage again next time out 

[Realtimedoctor]

On 15/04/2022 at 23:42, 04Stefan07 said:

I am currently using an HEQ5 Pro and have it powered via my Pocket Powerbox Advanced. I have a few devices plugged into it and I get a max of 11.8V during my imaging sessions.

When slewing however it drops to 11.6V and that's when the mount's power light starts to flash. I have also noticed when imaging/guiding you can hear the mount make some noise and sometimes the power light will go off very quickly when it makes the noise and come back.

Would I be better off running dedicated power for my mount and not use the power box or should I be puchasing the "certified" power supply that Pegasus Astro recommends? I do have a spare power outlet at the telescope but in the end I am trying to reduce the amount of cabling and power packs needed for my setup.

Would the power supply they sell guarentee me 11.9 to 12V of steady power?

I know this is going to sound daft, but are you sure you've not connected the power input into the adjustable power out port? 

 

It's a very easy mistake to do, and will cause power drop esp on the gen 2 PPBA. 

I suffered from similar issues, using a generic power supply, ended up ordering the pegasus PSU, had the same issues power dropping. 

Finally figured out that the I had mistakenly plugged into the adjustable output port while doing cable management, and didn't realise the mistake as PPBA still powers up and goes everything is supposed to do, bar the voltage drop causing a system reset. 

Hope this helps, 

Cheers, 

Nish 

 

EDIT - Pegasus PSU supplies 13.0v flat, and is very well made with 12awg wire. 

Edited April 18, 2022 by Realtimedoctor

[04Stefan07]

33 minutes ago, Realtimedoctor said:

I know this is going to sound daft, but are you sure you've not connected the power input into the adjustable power out port? 

 

It's a very easy mistake to do, and will cause power drop esp on the gen 2 PPBA. 

I suffered from similar issues, using a generic power supply, ended up ordering the pegasus PSU, had the same issues power dropping. 

Finally figured out that the I had mistakenly plugged into the adjustable output port while doing cable management, and didn't realise the mistake as PPBA still powers up and goes everything is supposed to do, bar the voltage drop causing a system reset. 

Hope this helps, 

Cheers, 

Nish 

 

EDIT - Pegasus PSU supplies 13.0v flat, and is very well made with 12awg wire. 

Yeah I did this exact same thing before, my voltage was around 11.4 then realised I had it plugged into the adjustable output.

Unfortunately not on this occasion.

I was skeptical about the Pegasus power supplies, they look like a standard on you can buy anywhere. Are they any good?