Electric fence "Electric Shepherd" ESB 250

N

N_Cook

Guest
Before wasting time on this, de-rivetting the step up transformer mounting
etc.
Input side measures 5Mohm, HV output side 12.7R, but looks like a standard
mains transformer.
Would this be a purpose wound transformer or an off the shelf mains
transformer that could be replaced with similar, if so what sort of voltages
and which way round ?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
N_Cook wrote:
Before wasting time on this, de-rivetting the step up transformer mounting
etc.
Input side measures 5Mohm, HV output side 12.7R, but looks like a standard
mains transformer.
Click to expand...

Shouldn't that be the other way round?


Would this be a purpose wound transformer or an off the shelf mains
transformer that could be replaced with similar, if so what sort of voltages
and which way round ?
Click to expand...
They might have just used a low volts to mains tranny the 'wrong way round'

Ron
 
Ron Johnson <ron@lunevalleyaudio.com> wrote in message
news:buudnaUWdIS8d8XUnZ2dnUVZ8rKdnZ2d@bt.com...
N_Cook wrote:
Before wasting time on this, de-rivetting the step up transformer
mounting
etc.
Input side measures 5Mohm, HV output side 12.7R, but looks like a
standard
mains transformer.


Shouldn't that be the other way round?


Would this be a purpose wound transformer or an off the shelf mains
transformer that could be replaced with similar, if so what sort of
voltages
and which way round ?

They might have just used a low volts to mains tranny the 'wrong way
round'

Ron
Click to expand...

5M indicating a break associated with damp air getting in there.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
N_Cook wrote:

Before wasting time on this, de-rivetting the step up transformer
mounting etc.
Input side measures 5Mohm, HV output side 12.7R, but looks like a
standard mains transformer.
Would this be a purpose wound transformer or an off the shelf mains
transformer that could be replaced with similar, if so what sort of
voltages and which way round ?
Click to expand...
In the ones I built I used a standard car ignition coil ! 12 volt
battery and 1 pulse per second into it !

--
Best Regards:
Baron.
 
Baron <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:gjaulb$tpp$1@news.motzarella.org...
N_Cook wrote:


Before wasting time on this, de-rivetting the step up transformer
mounting etc.
Input side measures 5Mohm, HV output side 12.7R, but looks like a
standard mains transformer.
Would this be a purpose wound transformer or an off the shelf mains
transformer that could be replaced with similar, if so what sort of
voltages and which way round ?

In the ones I built I used a standard car ignition coil ! 12 volt
battery and 1 pulse per second into it !

--
Best Regards:
Baron.
Click to expand...

As I cannot see how the high current side of a mains transformer could fail
I drilled out the rivets.
If originally a mains transformer, looks like one , it had primary 0.4mm
wire and secondary 0.9mm wire. 0.9mm wire has failed .
For a , by size , 50W transformer I make that 24V, 2 amp if for a 240V
transformer.
Vs = (Vp/2) * (Dp/Ds)^2 , Is = P / Vs
Fence output voltage not stated on the label. 9 seriesed 0.22 nF (no V
stated) across the output and also 4.7K, 1W dropper to 2 seriously blackened
neons in series - any guesses what that indicates as an idea of o/p voltage
?
No obvious visible reason for failure of 0.9mm wire, I would expect the
0.4mm wire to fail.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
Well I would not have believed it unless personally witnessed.
As the o/c must be on the outer layer of the transformer, I stripped off the
cloth tape. There is indication that damp air has got in this unit but not
flooding or internal drips. But in the middle of this outer layer, with no
sign of corrosion or damp under the tape , generally, there is one spot of
blue green corrossion and a small break in the 0.9mm wire.
Maybe a spot of acidic something at that point on assembly and then years of
damp air. Bridging the break gives resistance of the winding of about 0.2
ohm.
Powering on a variac, could not take higher than 150V (saturating) so
assuming it is 110V transformer ( or problem on the original pimary ) output
read 4.7V ac , no load, for 110V ac input.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
N_Cook wrote:

Well I would not have believed it unless personally witnessed.
As the o/c must be on the outer layer of the transformer, I stripped
off the cloth tape. There is indication that damp air has got in this
unit but not flooding or internal drips. But in the middle of this
outer layer, with no sign of corrosion or damp under the tape ,
generally, there is one spot of blue green corrossion and a small
break in the 0.9mm wire. Maybe a spot of acidic something at that
point on assembly and then years of damp air.
Click to expand...
I have seen that type of failure in several instances, not just on
transformer windings ! PCB traces as well. I belive that acid flux has
been used locally and spattered during soldering. Possibly onto the
tape and then transfered to the wire.

Bridging the break gives
resistance of the winding of about 0.2 ohm.
Powering on a variac, could not take higher than 150V (saturating) so
assuming it is 110V transformer ( or problem on the original pimary )
output read 4.7V ac , no load, for 110V ac input.
Click to expand...
I'm a little surprised that it could be a 110V Txf... Or is it a unit
made in the USA ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
Click to expand...
--
Best Regards:
Baron.
 
Baron <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:gje9ml$m79$1@news.motzarella.org...
N_Cook wrote:

Well I would not have believed it unless personally witnessed.
As the o/c must be on the outer layer of the transformer, I stripped
off the cloth tape. There is indication that damp air has got in this
unit but not flooding or internal drips. But in the middle of this
outer layer, with no sign of corrosion or damp under the tape ,
generally, there is one spot of blue green corrossion and a small
break in the 0.9mm wire. Maybe a spot of acidic something at that
point on assembly and then years of damp air.

I have seen that type of failure in several instances, not just on
transformer windings ! PCB traces as well. I belive that acid flux has
been used locally and spattered during soldering. Possibly onto the
tape and then transfered to the wire.

Bridging the break gives
resistance of the winding of about 0.2 ohm.
Powering on a variac, could not take higher than 150V (saturating) so
assuming it is 110V transformer ( or problem on the original pimary )
output read 4.7V ac , no load, for 110V ac input.

I'm a little surprised that it could be a 110V Txf... Or is it a unit
made in the USA ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

--
Best Regards:
Baron.
Click to expand...
Back working with proper bridged repair, new neons etc . I'm asuming 8KV (it
is actually mentioned on the label) , at least it fires a neon via 100M ,
(0.1G ) dropper, I will dig out EHT divider today. The casing screws mayvbe
UNC which may indicate USA but label has UK address. Electric Shepherd
printed on the PCBs


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
1000:1 EHT divider to scope showed about 1.5V pulses which presumably is
consistent with no load 8KV. Left the bank of Cs and neons in circuit ,
giving about 1.5Kv peak pulse.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
On Wed, 31 Dec 2008 08:26:59 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Back working with proper bridged repair, new neons etc . I'm asuming 8KV (it
is actually mentioned on the label) , at least it fires a neon via 100M ,
(0.1G ) dropper, I will dig out EHT divider today. The casing screws mayvbe
UNC which may indicate USA but label has UK address. Electric Shepherd
printed on the PCBs
Click to expand...
FWIW the following device has an open output voltage of 8kV.

Electric Shepherd ESB25 Battery Fence Energiser:
http://www.rutland-electric-fencing.co.uk/PageProductDetail.aspx?ProductID=288&ReturnToListURL=PageSearch@2Easpx@3FProductSearchText@3Desb25&ProductListTypeName=SearchProductList,%20App_Code,%20Version=0.0.0.0,%20Culture=neutral,%20PublicKeyToken=null&IncludeDealersOnly=False&ProductSearchText=esb25

I have an electric fence controller kit that works by charging a 7uF
"dump" capacitor to 340V and then discharging it into the primary of
the HV transformer. The energy stored by the cap is ...

E = 0.5 x C x V x V = 0.40J

Its output voltage peaks at 3.6kV.

The ESB25 is spec'ed at 0.08 Joules, so perhaps you can work out the
required capacitor voltage (= transformer primary voltage) as follows:

V = sqrt( 0.08 x 2 / C)

Assuming V = 110V, then C = 13uF.

What is the rated DC voltage of your dump capacitor, assuming yours is
a similar design?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:55kol4h0ob2n20hvm3e71alo74tl3o3t4h@4ax.com...
On Wed, 31 Dec 2008 08:26:59 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Back working with proper bridged repair, new neons etc . I'm asuming 8KV
(it
is actually mentioned on the label) , at least it fires a neon via 100M ,
(0.1G ) dropper, I will dig out EHT divider today. The casing screws
mayvbe
UNC which may indicate USA but label has UK address. Electric Shepherd
printed on the PCBs

FWIW the following device has an open output voltage of 8kV.

Electric Shepherd ESB25 Battery Fence Energiser:

http://www.rutland-electric-fencing.co.uk/PageProductDetail.aspx?ProductID=2
Click to expand...
88&ReturnToListURL=PageSearch@2Easpx@3FProductSearchText@3Desb25&ProductList
TypeName=SearchProductList,%20App_Code,%20Version=0.0.0.0,%20Culture=neutral
,%20PublicKeyToken=null&IncludeDealersOnly=False&ProductSearchText=esb25
I have an electric fence controller kit that works by charging a 7uF
"dump" capacitor to 340V and then discharging it into the primary of
the HV transformer. The energy stored by the cap is ...

E = 0.5 x C x V x V = 0.40J

Its output voltage peaks at 3.6kV.

The ESB25 is spec'ed at 0.08 Joules, so perhaps you can work out the
required capacitor voltage (= transformer primary voltage) as follows:

V = sqrt( 0.08 x 2 / C)

Assuming V = 110V, then C = 13uF.

What is the rated DC voltage of your dump capacitor, assuming yours is
a similar design?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
Click to expand...
All boxed up now but from my listing of major devices it is 20uF, 400V
Of course the 110V primary is now used as the secondary here, for th
evoltage step-up. Internal construction looked the same as mains
transformer.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
On Thu, 1 Jan 2009 08:39:30 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Franc Zabkar <fzabkar@iinternode.on.net> wrote in message
news:55kol4h0ob2n20hvm3e71alo74tl3o3t4h@4ax.com...
On Wed, 31 Dec 2008 08:26:59 -0000, "N_Cook" <diverse@tcp.co.uk> put
finger to keyboard and composed:

Back working with proper bridged repair, new neons etc . I'm asuming 8KV
(it
is actually mentioned on the label) , at least it fires a neon via 100M ,
(0.1G ) dropper, I will dig out EHT divider today. The casing screws
mayvbe
UNC which may indicate USA but label has UK address. Electric Shepherd
printed on the PCBs

FWIW the following device has an open output voltage of 8kV.

Electric Shepherd ESB25 Battery Fence Energiser:

http://www.rutland-electric-fencing.co.uk/PageProductDetail.aspx?ProductID=2
88&ReturnToListURL=PageSearch@2Easpx@3FProductSearchText@3Desb25&ProductList
TypeName=SearchProductList,%20App_Code,%20Version=0.0.0.0,%20Culture=neutral
,%20PublicKeyToken=null&IncludeDealersOnly=False&ProductSearchText=esb25

I have an electric fence controller kit that works by charging a 7uF
"dump" capacitor to 340V and then discharging it into the primary of
the HV transformer. The energy stored by the cap is ...

E = 0.5 x C x V x V = 0.40J

Its output voltage peaks at 3.6kV.

The ESB25 is spec'ed at 0.08 Joules, so perhaps you can work out the
required capacitor voltage (= transformer primary voltage) as follows:

V = sqrt( 0.08 x 2 / C)

Assuming V = 110V, then C = 13uF.

What is the rated DC voltage of your dump capacitor, assuming yours is
a similar design?

All boxed up now but from my listing of major devices it is 20uF, 400V
Of course the 110V primary is now used as the secondary here, for th
evoltage step-up. Internal construction looked the same as mains
transformer.
Click to expand...
Assuming that the energy output of the ESB250 is the same as the
ESB25, then I calculate that the charging voltage should be 90VDC.
This seems low for a 400V cap. Maybe you should enquire as to the
actual energy rating.

FWIW, the ESB15 energiser is rated at 0.05J:
http://www.rutland-electric-fencing.co.uk/PageProductDetail.aspx?ProductID=279&ReturnToListURL=PageProductDetail@2Easpx@3FProductID@3D289@26ReturnToListURL@3DPageProductList@402Easpx@403FSelectedTab@403DTopTab@405F3@405F7@405F1@26ProductListTypeName@3DZarebaCommon@2ESiteCategoryProductList@2C@2520ZarebaCommon@2C@2520Version@3D1@2E0@2E0@2E0@2C@2520Culture@3Dneutral@2C@2520PublicKeyToken@3Dnull@26IncludeDealersOnly@3DFalse@26SiteID@3D2@26SiteCategoryID@3D25&IncludeDealersOnly=False&BaseProductID=289
http://preview.tinyurl.com/9xkv7d

Rutland's recommendations seem inconsistent:
http://www.rutland-electric-fencing.co.uk/PageAnimalCattle.aspx

"As a very general guide, the energiser powering a permanent fence
should have a stored energy of not less than 0.5 joules for cattle
...."

"Dairy cattle being strip grazed can usually be contained with a
single conductor of poly wire or 12mm poly tape, powered by an
energiser of around 0.25 Joules or less provided the voltage on the
fence is around 2,000 - 3000volts."

BTW, if you ever need to source a replacement transformer, then maybe
you could consider an old Philips FBT of the type that required a
tripler. Those would have had an output of 8kV (25kV / 3), and the B+
would have been 155V or less.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
On Jan 1, 7:17 pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:
On Thu, 1 Jan 2009 08:39:30 -0000, "N_Cook" <dive...@tcp.co.uk> put
finger to keyboard and composed:





Franc Zabkar <fzab...@iinternode.on.net> wrote in message
news:55kol4h0ob2n20hvm3e71alo74tl3o3t4h@4ax.com...
On Wed, 31 Dec 2008 08:26:59 -0000, "N_Cook" <dive...@tcp.co.uk> put
finger to keyboard and composed:

Back working with proper bridged repair, new neons etc . I'm asuming 8KV
(it
is actually mentioned on the label) , at least it fires a neon via 100M ,
(0.1G ) dropper, I will dig out EHT divider today. The casing screws
mayvbe
UNC which may indicate USA but label has UK address. Electric Shepherd
printed on the PCBs

FWIW the following device has an open output voltage of 8kV.

Electric Shepherd ESB25 Battery Fence Energiser:

http://www.rutland-electric-fencing.co.uk/PageProductDetail.aspx?Prod...
88&ReturnToListURL=PageSearch@2Easpx@3FProductSearchText@3Desb25&ProductLi­st
TypeName=SearchProductList,%20App_Code,%20Version=0.0.0.0,%20Culture=neutr­al
,%20PublicKeyToken=null&IncludeDealersOnly=False&ProductSearchText=esb25

I have an electric fence controller kit that works by charging a 7uF
"dump" capacitor to 340V and then discharging it into the primary of
the HV transformer. The energy stored by the cap is ...

 E  = 0.5 x C x V x V = 0.40J

Its output voltage peaks at 3.6kV.

The ESB25 is spec'ed at 0.08 Joules, so perhaps you can work out the
required capacitor voltage (= transformer primary voltage) as follows:

 V = sqrt( 0.08 x 2 / C)

Assuming V = 110V, then C = 13uF.

What is the rated DC voltage of your dump capacitor, assuming yours is
a similar design?
All boxed up now but from my listing of major devices it is 20uF, 400V
Of course the 110V primary is now used as the secondary here, for th
evoltage step-up. Internal construction looked the same as mains
transformer.

Assuming that the energy output of the ESB250 is the same as the
ESB25, then I calculate that the charging voltage should be 90VDC.
This seems low for a 400V cap. Maybe you should enquire as to the
actual energy rating.

FWIW, the ESB15 energiser is rated at 0.05J:http://www.rutland-electric-fencing.co.uk/PageProductDetail.aspx?Prod...http://preview.tinyurl.com/9xkv7d

Rutland's recommendations seem inconsistent:http://www.rutland-electric-fencing.co.uk/PageAnimalCattle.aspx

"As a very general guide, the energiser powering a permanent fence
should have a stored energy of not less than 0.5 joules for cattle
..."

"Dairy cattle being strip grazed can usually be contained with a
single conductor of poly wire or 12mm poly tape, powered by an
energiser of around 0.25 Joules or less provided the voltage on the
fence is around 2,000 - 3000volts."

BTW, if you ever need to source a replacement transformer, then maybe
you could consider an old Philips FBT of the type that required a
tripler. Those would have had an output of 8kV (25kV / 3), and the B+
would have been 155V or less.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.- Hide quoted text -

- Show quoted text -
Click to expand...
I have a problem with the ESB 55 version. I believe that the thyristor
has blown. It seems to be an 82516 from ST Philips but has been
discontinued. Does anybody know of an alternative??? The two neons
have also blackened but I do not know what to replace them with. Could
you let me know what you used please. Many thanks. Jeff.
 
I have a problem with the ESB 55 version. I believe that the thyristor
has blown. It seems to be an 82516 from ST Philips but has been
discontinued. Does anybody know of an alternative??? The two neons
have also blackened but I do not know what to replace them with. Could
you let me know what you used please. Many thanks. Jeff.

++++++

I just replaced the pair with a couple of standard mains indicator ones ,
without any dropper, just the original dropper which probably should have a
higher ohmic value. But as used outdoor, to see them flash then necessary,
then probably a matter of replacing the neons when necessary

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/
 
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